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2017-04-20of/acpi: Configure dma operations at probe time for platform/amba/pci bus ↵Sricharan R
devices Configuring DMA ops at probe time will allow deferring device probe when the IOMMU isn't available yet. The dma_configure for the device is now called from the generic device_attach callback just before the bus/driver probe is called. This way, configuring the DMA ops for the device would be called at the same place for all bus_types, hence the deferred probing mechanism should work for all buses as well. pci_bus_add_devices (platform/amba)(_device_create/driver_register) | | pci_bus_add_device (device_add/driver_register) | | device_attach device_initial_probe | | __device_attach_driver __device_attach_driver | driver_probe_device | really_probe | dma_configure Similarly on the device/driver_unregister path __device_release_driver is called which inturn calls dma_deconfigure. This patch changes the dma ops configuration to probe time for both OF and ACPI based platform/amba/pci bus devices. Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci part) Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sricharan R <sricharan@codeaurora.org> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-01-14Revert "driver core: Add deferred_probe attribute to devices in sysfs"Greg Kroah-Hartman
This reverts commit 6751667a29d6fd64afb9ce30567ad616b68ed789. Rob Herring objected to it, and a replacement for it will be added using debugfs in the future. Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Reported-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-13Merge tag 'driver-core-4.10-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here's the new driver core patches for 4.10-rc1. Big thing here is the nice addition of "functional dependencies" to the driver core. The idea has been talked about for a very long time, great job to Rafael for stepping up and implementing it. It's been tested for longer than the 4.9-rc1 date, we held off on merging it earlier in order to feel more comfortable about it. Other than that, it's just a handful of small other patches, some good cleanups to the mess that is the firmware class code, and we have a test driver for the deferred probe logic. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (30 commits) firmware: Correct handling of fw_state_wait() return value driver core: Silence device links sphinx warning firmware: remove warning at documentation generation time drivers: base: dma-mapping: Fix typo in dmam_alloc_non_coherent comments driver core: test_async: fix up typo found by 0-day firmware: move fw_state_is_done() into UHM section firmware: do not use fw_lock for fw_state protection firmware: drop bit ops in favor of simple state machine firmware: refactor loading status firmware: fix usermode helper fallback loading driver core: firmware_class: convert to use class_groups driver core: devcoredump: convert to use class_groups driver core: class: add class_groups support kernfs: Declare two local data structures static driver-core: fix platform_no_drv_owner.cocci warnings drivers/base/memory.c: Remove unused 'first_page' variable driver core: add CLASS_ATTR_WO() drivers: base: cacheinfo: support DT overrides for cache properties drivers: base: cacheinfo: add pr_fmt logging drivers: base: cacheinfo: fix boot error message when acpi is enabled ...
2016-11-10driver core: Add deferred_probe attribute to devices in sysfsBen Hutchings
It is sometimes useful to know that a device is on the deferred probe list rather than, say, not having a driver available. Expose this information to user-space. Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31PM / runtime: Use device linksRafael J. Wysocki
Modify the runtime PM framework to use device links to ensure that supplier devices will not be suspended if any of their consumer devices are active. The idea is to reference count suppliers on the consumer's resume and drop references to them on its suspend. The information on whether or not the supplier has been reference counted by the consumer's (runtime) resume is stored in a new field (rpm_active) in the link object for each link. It may be necessary to clean up those references when the supplier is unbinding and that's why the links whose status is DEVICE_LINK_SUPPLIER_UNBIND are skipped by the runtime suspend and resume code. The above means that if the consumer device is probed in the runtime-active state, the supplier has to be resumed and reference counted by device_link_add() so the code works as expected on its (runtime) suspend. There is a new flag, DEVICE_LINK_RPM_ACTIVE, to tell device_link_add() about that (in which case the caller is responsible for making sure that the consumer really will be runtime-active when runtime PM is enabled for it). The other new link flag, DEVICE_LINK_PM_RUNTIME, tells the core whether or not the link should be used for runtime PM at all. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31driver core: Functional dependencies tracking supportRafael J. Wysocki
Currently, there is a problem with taking functional dependencies between devices into account. What I mean by a "functional dependency" is when the driver of device B needs device A to be functional and (generally) its driver to be present in order to work properly. This has certain consequences for power management (suspend/resume and runtime PM ordering) and shutdown ordering of these devices. In general, it also implies that the driver of A needs to be working for B to be probed successfully and it cannot be unbound from the device before the B's driver. Support for representing those functional dependencies between devices is added here to allow the driver core to track them and act on them in certain cases where applicable. The argument for doing that in the driver core is that there are quite a few distinct use cases involving device dependencies, they are relatively hard to get right in a driver (if one wants to address all of them properly) and it only gets worse if multiplied by the number of drivers potentially needing to do it. Morever, at least one case (asynchronous system suspend/resume) cannot be handled in a single driver at all, because it requires the driver of A to wait for B to suspend (during system suspend) and the driver of B to wait for A to resume (during system resume). For this reason, represent dependencies between devices as "links", with the help of struct device_link objects each containing pointers to the "linked" devices, a list node for each of them, status information, flags, and an RCU head for synchronization. Also add two new list heads, representing the lists of links to the devices that depend on the given one (consumers) and to the devices depended on by it (suppliers), and a "driver presence status" field (needed for figuring out initial states of device links) to struct device. The entire data structure consisting of all of the lists of link objects for all devices is protected by a mutex (for link object addition/removal and for list walks during device driver probing and removal) and by SRCU (for list walking in other case that will be introduced by subsequent change sets). If CONFIG_SRCU is not selected, however, an rwsem is used for protecting the entire data structure. In addition, each link object has an internal status field whose value reflects whether or not drivers are bound to the devices pointed to by the link or probing/removal of their drivers is in progress etc. That field is only modified under the device links mutex, but it may be read outside of it in some cases (introduced by subsequent change sets), so modifications of it are annotated with WRITE_ONCE(). New links are added by calling device_link_add() which takes three arguments: pointers to the devices in question and flags. In particular, if DL_FLAG_STATELESS is set in the flags, the link status is not to be taken into account for this link and the driver core will not manage it. In turn, if DL_FLAG_AUTOREMOVE is set in the flags, the driver core will remove the link automatically when the consumer device driver unbinds from it. One of the actions carried out by device_link_add() is to reorder the lists used for device shutdown and system suspend/resume to put the consumer device along with all of its children and all of its consumers (and so on, recursively) to the ends of those lists in order to ensure the right ordering between all of the supplier and consumer devices. For this reason, it is not possible to create a link between two devices if the would-be supplier device already depends on the would-be consumer device as either a direct descendant of it or a consumer of one of its direct descendants or one of its consumers and so on. There are two types of link objects, persistent and non-persistent. The persistent ones stay around until one of the target devices is deleted, while the non-persistent ones are removed automatically when the consumer driver unbinds from its device (ie. they are assumed to be valid only as long as the consumer device has a driver bound to it). Persistent links are created by default and non-persistent links are created when the DL_FLAG_AUTOREMOVE flag is passed to device_link_add(). Both persistent and non-persistent device links can be deleted with an explicit call to device_link_del(). Links created without the DL_FLAG_STATELESS flag set are managed by the driver core using a simple state machine. There are 5 states each link can be in: DORMANT (unused), AVAILABLE (the supplier driver is present and functional), CONSUMER_PROBE (the consumer driver is probing), ACTIVE (both supplier and consumer drivers are present and functional), and SUPPLIER_UNBIND (the supplier driver is unbinding). The driver core updates the link state automatically depending on what happens to the linked devices and for each link state specific actions are taken in addition to that. For example, if the supplier driver unbinds from its device, the driver core will also unbind the drivers of all of its consumers automatically under the assumption that they cannot function properly without the supplier. Analogously, the driver core will only allow the consumer driver to bind to its device if the supplier driver is present and functional (ie. the link is in the AVAILABLE state). If that's not the case, it will rely on the existing deferred probing mechanism to wait for the supplier driver to become available. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31driver core: fix smatch warning on dev->bus checkRob Herring
Commit d42a09802174 (driver core: skip removal test for non-removable drivers) introduced a smatch warning: drivers/base/dd.c:386 really_probe() warn: variable dereferenced before check 'dev->bus' (see line 373) Fix the warning by removing the dev->bus NULL check. dev->bus will never be NULL, so the check was unnecessary. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31driver core: skip removal test for non-removable driversRob Herring
Some drivers do not support removal/unbinding. These drivers should have drv->suppress_bind_attrs set to true, so use that to skip the removal test. This doesn't fix anything reported so far, but should prevent some other cases. Some drivers will need fixes to set suppress_bind_attrs to avoid this test. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=177021 Fixes: bea5b158ff0d ("driver core: add test of driver remove calls during probe") Reported-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28driver core: Add a wrapper around __device_release_driver()Rafael J. Wysocki
Add an internal wrapper around __device_release_driver() that will acquire device locks and do the necessary checks before calling it. The next patch will make use of it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-02device core: Remove deprecated create_singlethread_workqueueBhaktipriya Shridhar
The workqueue "deferred_wq" queues a single work item &deferred_probe_work and hence doesn't require ordering. It is involved in probing devices and is not being used on a memory reclaim path. Hence, it has been converted to use system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. The work item has been flushed in driver_probe_done() to ensure that there are no pending tasks while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31driver core: add test of driver remove calls during probeRob Herring
In recent discussions on ksummit-discuss[1], it was suggested to do a sequence of probe, remove, probe for testing driver remove paths. This adds a kconfig option for said test. [1] https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2016-August/003459.html Suggested-by: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-16ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()Tomeu Vizoso
Allow implementations of the match() callback in struct bus_type to return errors and if it's -EPROBE_DEFER then queue the device for deferred probing. This is useful to buses such as AMBA in which devices are registered before their matching information can be retrieved from the HW (typically because a clock driver hasn't probed yet). [changed if-else code structure, adjusted documentation to match the code, extended comments] Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-01-12driver core: Avoid NULL pointer dereferences in device_is_bound()Rafael J. Wysocki
If device_is_bound() is called on a device that's not been registered yet, it will attepmt to dereference dev->p which is NULL, so avoid that by checking dev->p in there against NULL. Fixes: 6b9cb42752da "device core: add device_is_bound()" Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-08PM / sleep: Go direct_complete if driver has no callbacksTomeu Vizoso
If a suitable prepare callback cannot be found for a given device and its driver has no PM callbacks at all, assume that it can go direct to complete when the system goes to sleep. The reason for this is that there's lots of devices in a system that do no PM at all and there's no reason for them to prevent their ancestors to do direct_complete if they can support it. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-08device core: add device_is_bound()Tomeu Vizoso
Adds a function that tells whether a device is already bound to a driver. This is needed to warn when there is an attempt to change the PM domain of a device that has finished probing already. The reason why we want to enforce that is because in the general case that can cause problems and also that we can simplify code quite a bit if we can always assume that. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-08Merge branch 'acpi-soc' into pm-coreRafael J. Wysocki
2015-12-09device core: add BUS_NOTIFY_DRIVER_NOT_BOUND notificationAndy Shevchenko
The users of BUS_NOTIFY_BIND_DRIVER have no chance to do any cleanup in case of a probe failure. In the result there might be problems, such as some resources that had been allocated will continue to be allocated and therefore lead to a resource leak. Introduce a new notification to inform the subscriber that ->probe() failed. Do the same in case of failed device_bind_driver() call. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-07Merge branches 'pm-sleep' and 'pm-runtime' into pm-coreRafael J. Wysocki
2015-11-30PM / runtime: Re-init runtime PM states at probe error and driver unbindUlf Hansson
There are two common expectations among several subsystems/drivers that deploys runtime PM support, but which isn't met by the driver core. Expectation 1) At ->probe() the subsystem/driver expects the runtime PM status of the device to be RPM_SUSPENDED, which is the initial status being assigned at device registration. This expectation is especially common among some of those subsystems/ drivers that manages devices with an attached PM domain, as those requires the ->runtime_resume() callback at the PM domain level to be invoked during ->probe(). Moreover these subsystems/drivers entirely relies on runtime PM resources being managed at the PM domain level, thus don't implement their own set of runtime PM callbacks. These are two scenarios that suffers from this unmet expectation. i) A failed ->probe() sequence requests probe deferral: ->probe() ... pm_runtime_enable() pm_runtime_get_sync() ... err: pm_runtime_put() pm_runtime_disable() ... As there are no guarantees that such sequence turns the runtime PM status of the device into RPM_SUSPENDED, the re-trying ->probe() may start with the status in RPM_ACTIVE. In such case the runtime PM core won't invoke the ->runtime_resume() callback because of a pm_runtime_get_sync(), as it considers the device to be already runtime resumed. ii) A driver re-bind sequence: At driver unbind, the subsystem/driver's >remove() callback invokes a sequence of runtime PM APIs, to undo actions during ->probe() and to put the device into low power state. ->remove() ... pm_runtime_put() pm_runtime_disable() ... Similar as in the failing ->probe() case, this sequence don't guarantee the runtime PM status of the device to turn into RPM_SUSPENDED. Trying to re-bind the driver thus causes the same issue as when re-trying ->probe(), in the probe deferral scenario. Expectation 2) Drivers that invokes the pm_runtime_irq_safe() API during ->probe(), triggers the runtime PM core to increase the usage count for the device's parent and permanently make it runtime resumed. The usage count is only dropped at device removal, which also allows it to be runtime suspended again. A re-trying ->probe() repeats the call to pm_runtime_irq_safe() and thus once more triggers the usage count of the device's parent to be increased. This leads to not only an imbalance issue of the usage count of the device's parent, but also to keep it runtime resumed permanently even if ->probe() fails. To address these issues, let's change the policy of the driver core to meet these expectations. More precisely, at ->probe() failures and driver unbind, restore the initial states of runtime PM. Although to still allow subsystem's to control PM for devices that doesn't ->probe() successfully, don't restore the initial states unless runtime PM is disabled. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-30PM / sleep: prohibit devices probing during suspend/hibernationStrashko, Grygorii
It is unsafe [1] if probing of devices will happen during suspend or hibernation and system behavior will be unpredictable in this case. So, let's prohibit device's probing in dpm_prepare() and defer their probing instead. The normal behavior will be restored in dpm_complete(). This patch introduces new DD core APIs: device_block_probing() It will disable probing of devices and defer their probes instead. device_unblock_probing() It will restore normal behavior and trigger re-probing of deferred devices. [1] https://lkml.org/lkml/2015/9/11/554 Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-27drivers/pinctrl: Add the concept of an "init" stateDouglas Anderson
For pinctrl the "default" state is applied to pins before the driver's probe function is called. This is normally a sensible thing to do, but in some cases can cause problems. That's because the pins will change state before the driver is given a chance to program how those pins should behave. As an example you might have a regulator that is controlled by a PWM (output high = high voltage, output low = low voltage). The firmware might leave this pin as driven high. If we allow the driver core to reconfigure this pin as a PWM pin before the PWM's probe function runs then you might end up running at too low of a voltage while we probe. Let's introudce a new "init" state. If this is defined we'll set pinctrl to this state before probe and then "default" after probe (unless the driver explicitly changed states already). An alternative idea that was thought of was to use the pre-existing "sleep" or "idle" states and add a boolean property that we should start in that mode. This was not done because the "init" state is needed for correctness and those other states are only present (and only transitioned in to and out of) when (optional) power management is enabled. Changes in v3: - Moved declarations to pinctrl/devinfo.h - Fixed author/SoB Changes in v2: - Added comment to pinctrl_init_done() as per Linus W. Signed-off-by: Douglas Anderson <dianders@chromium.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Caesar Wang <wxt@rock-chips.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-09-01Merge tag 'pm+acpi-4.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "From the number of commits perspective, the biggest items are ACPICA and cpufreq changes with the latter taking the lead (over 50 commits). On the cpufreq front, there are many cleanups and minor fixes in the core and governors, driver updates etc. We also have a new cpufreq driver for Mediatek MT8173 chips. ACPICA mostly updates its debug infrastructure and adds a number of fixes and cleanups for a good measure. The Operating Performance Points (OPP) framework is updated with new DT bindings and support for them among other things. We have a few updates of the generic power domains framework and a reorganization of the ACPI device enumeration code and bus type operations. And a lot of fixes and cleanups all over. Included is one branch from the MFD tree as it contains some PM-related driver core and ACPI PM changes a few other commits are based on. Specifics: - ACPICA update to upstream revision 20150818 including method tracing extensions to allow more in-depth AML debugging in the kernel and a number of assorted fixes and cleanups (Bob Moore, Lv Zheng, Markus Elfring). - ACPI sysfs code updates and a documentation update related to AML method tracing (Lv Zheng). - ACPI EC driver fix related to serialized evaluations of _Qxx methods and ACPI tools updates allowing the EC userspace tool to be built from the kernel source (Lv Zheng). - ACPI processor driver updates preparing it for future introduction of CPPC support and ACPI PCC mailbox driver updates (Ashwin Chaugule). - ACPI interrupts enumeration fix for a regression related to the handling of IRQ attribute conflicts between MADT and the ACPI namespace (Jiang Liu). - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi Kasagar). - ACPI device registration code reorganization to separate the sysfs-related code and bus type operations from the rest (Rafael J Wysocki). - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause, Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss). - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan Xinhui, Rafael J Wysocki). - cpufreq core cleanups on top of the previous changes allowing it to preseve its sysfs directories over system suspend/resume (Viresh Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior). - cpufreq fixes and cleanups related to governors (Viresh Kumar). - cpufreq updates (core and the cpufreq-dt driver) related to the turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz). - New DT bindings for Operating Performance Points (OPP), support for them in the OPP framework and in the cpufreq-dt driver plus related OPP framework fixes and cleanups (Viresh Kumar). - cpufreq powernv driver updates (Shilpasri G Bhat). - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen). - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean). - intel_pstate driver updates including Skylake-S support, support for enabling HW P-states per CPU and an additional vendor bypass list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao). - cpuidle core fixes related to the handling of coupled idle states (Xunlei Pang). - intel_idle driver updates including Skylake Client support and support for freeze-mode-specific idle states (Len Brown). - Driver core updates related to power management (Andy Shevchenko, Rafael J Wysocki). - Generic power domains framework fixes and cleanups (Jon Hunter, Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson). - Device PM QoS framework update to allow the latency tolerance setting to be exposed to user space via sysfs (Mika Westerberg). - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas). - System sleep support updates (Alan Stern, Len Brown, SungEun Kim). - rockchip-io AVS support updates (Heiko Stuebner). - PM core clocks support fixup (Colin Ian King). - Power capping RAPL driver update including support for Skylake H/S and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi). - Generic device properties framework fixes related to the handling of static (driver-provided) property sets (Andy Shevchenko). - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat, Shreyas B Prabhu)" * tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits) cpufreq: speedstep-lib: Use monotonic clock cpufreq: powernv: Increase the verbosity of OCC console messages cpufreq: sfi: use kmemdup rather than duplicating its implementation cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor() cpufreq: rename cpufreq_real_policy as cpufreq_user_policy cpufreq: remove redundant 'policy' field from user_policy cpufreq: remove redundant 'governor' field from user_policy cpufreq: update user_policy.* on success cpufreq: use memcpy() to copy policy cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event cpufreq: mediatek: Add MT8173 cpufreq driver dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings PM / Domains: Fix typo in description of genpd_dev_pm_detach() PM / Domains: Remove unusable governor dummies PM / Domains: Make pm_genpd_init() available to modules PM / domains: Align column headers and data in pm_genpd_summary output powercap / RAPL: disable the 2nd power limit properly tools: cpupower: Fix error when running cpupower monitor PM / OPP: Drop unlikely before IS_ERR(_OR_NULL) PM / OPP: Fix static checker warning (broken 64bit big endian systems) ...
2015-08-05driver core: correct device's shutdown orderGrygorii Strashko
Now device's shutdown sequence is performed in reverse order of their registration in devices_kset list and this sequence corresponds to the reverse device's creation order. So, devices_kset data tracks "parent<-child" device's dependencies only. Unfortunately, that's not enough and causes problems in case of implementing board's specific shutdown procedures. For example [1]: "DRA7XX_evm uses PCF8575 and one of the PCF output lines feeds to MMC/SD and this line should be driven high in order for the MMC/SD to be detected. This line is modelled as regulator and the hsmmc driver takes care of enabling and disabling it. In the case of 'reboot', during shutdown path as part of it's cleanup process the hsmmc driver disables this regulator. This makes MMC boot not functional." To handle this issue the .shutdown() callback could be implemented for PCF8575 device where corresponding GPIO pins will be configured to states, required for correct warm/cold reset. This can be achieved only when all .shutdown() callbacks have been called already for all PCF8575's consumers. But devices_kset is not filled correctly now: devices_kset: Device61 4e000000.dmm devices_kset: Device62 48070000.i2c devices_kset: Device63 48072000.i2c devices_kset: Device64 48060000.i2c devices_kset: Device65 4809c000.mmc ... devices_kset: Device102 fixedregulator-sd ... devices_kset: Device181 0-0020 // PCF8575 devices_kset: Device182 gpiochip496 devices_kset: Device183 0-0021 // PCF8575 devices_kset: Device184 gpiochip480 As can be seen from above .shutdown() callback for PCF8575 will be called before its consumers, which, in turn means, that any changes of PCF8575 GPIO's pins will be or unsafe or overwritten later by GPIO's consumers. The problem can be solved if devices_kset list will be filled not only according device creation order, but also according device's probing order to track "supplier<-consumer" dependencies also. Hence, as a fix, lets add devices_kset_move_last(), devices_kset_move_before(), devices_kset_move_after() and call them from device_move() and also add call of devices_kset_move_last() in really_probe(). After this change all entries in devices_kset will be sorted according to device's creation ("parent<-child") and probing ("supplier<-consumer") order. devices_kset after: devices_kset: Device121 48070000.i2c devices_kset: Device122 i2c-0 ... devices_kset: Device147 regulator.24 devices_kset: Device148 0-0020 devices_kset: Device149 gpiochip496 devices_kset: Device150 0-0021 devices_kset: Device151 gpiochip480 devices_kset: Device152 0-0019 ... devices_kset: Device372 fixedregulator-sd devices_kset: Device373 regulator.29 devices_kset: Device374 4809c000.mmc devices_kset: Device375 mmc0 [1] http://www.spinics.net/lists/linux-mmc/msg29825.html Cc: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-28Driver core: wakeup the parent device before trying probeRafael J. Wysocki
If the parent is still suspended when driver probe is attempted, the result may be failure. For example, if the parent is a PCI MFD device that has been suspended when we try to probe our device, any register reads will return 0xffffffff. To fix the problem, making sure the parent is always awake before attempting driver probe. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-06-01base:dd - Fix for typo in comment to function driver_deferred_probe_trigger().Shailendra Verma
Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24driver-core: fix build for !CONFIG_MODULESDmitry Torokhov
Commit f2411da74698 ("driver-core: add driver module asynchronous probe support") broke build in case modules are disabled, because in this case "struct module" is not defined and we can't dereference it. Let's define module_requested_async_probing() helper and stub it out if modules are disabled. Reported-by: kbuild test robot <fengguang.wu@intel.com> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24driver-core: make __device_attach() staticDmitry Torokhov
It is only used within dd.c and thus need not be global. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20driver-core: enable drivers to opt-out of async probeLuis R. Rodriguez
There are drivers that can not be probed asynchronously. One such group is platform drivers registered with platform_driver_probe(), which expects driver's probe routine be discarded after the driver has been registered and initial binding attempt executed. Also platform_driver_probe() an error when no devices were bound to the driver, allowing failing to load such driver module altogether. Other drivers do not work well with asynchronous probing because of driver bug or not optimal driver organization. To allow using such drivers even when user requests asynchronous probing as default boot strategy, let's allow them to opt out. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20driver-core: add driver module asynchronous probe supportLuis R. Rodriguez
Some init systems may wish to express the desire to have device drivers run their probe() code asynchronously. This implements support for this and allows userspace to request async probe as a preference through a generic shared device driver module parameter, async_probe. Implementation for async probe is supported through a module parameter given that since synchronous probe has been prevalent for years some userspace might exist which relies on the fact that the device driver will probe synchronously and the assumption that devices it provides will be immediately available after this. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20driver-core: add asynchronous probing support for driversDmitry Torokhov
Some devices take a long time when initializing, and not all drivers are suited to initialize their devices when they are open. For example, input drivers need to interrogate their devices in order to publish device's capabilities before userspace will open them. When such drivers are compiled into kernel they may stall entire kernel initialization. This change allows drivers request for their probe functions to be called asynchronously during driver and device registration (manual binding is still synchronous). Because async_schedule is used to perform asynchronous calls module loading will still wait for the probing to complete. Note that the end goal is to make the probing asynchronous by default, so annotating drivers with PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us to speed up boot process while we validating and fixing the rest of the drivers and preparing userspace. This change is based on earlier patch by "Luis R. Rodriguez" <mcgrof@suse.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-14Merge tag 'pm+acpi-4.1-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "These are mostly fixes and cleanups all over, although there are a few items that sort of fall into the new feature category. First off, we have new callbacks for PM domains that should help us to handle some issues related to device initialization in a better way. There also is some consolidation in the unified device properties API area allowing us to use that inferface for accessing data coming from platform initialization code in addition to firmware-provided data. We have some new device/CPU IDs in a few drivers, support for new chips and a new cpufreq driver too. Specifics: - Generic PM domains support update including new PM domain callbacks to handle device initialization better (Russell King, Rafael J Wysocki, Kevin Hilman) - Unified device properties API update including a new mechanism for accessing data provided by platform initialization code (Rafael J Wysocki, Adrian Hunter) - ARM cpuidle update including ARM32/ARM64 handling consolidation (Daniel Lezcano) - intel_idle update including support for the Silvermont Core in the Baytrail SOC and for the Airmont Core in the Cherrytrail and Braswell SOCs (Len Brown, Mathias Krause) - New cpufreq driver for Hisilicon ACPU (Leo Yan) - intel_pstate update including support for the Knights Landing chip (Dasaratharaman Chandramouli, Kristen Carlson Accardi) - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann) - powernv cpufreq driver update (Shilpasri G Bhat) - devfreq update including Tegra support changes (Tomeu Vizoso, MyungJoo Ham, Chanwoo Choi) - powercap RAPL (Running-Average Power Limit) driver update including support for Intel Broadwell server chips (Jacob Pan, Mathias Krause) - ACPI device enumeration update related to the handling of the special PRP0001 device ID allowing DT-style 'compatible' property to be used for ACPI device identification (Rafael J Wysocki) - ACPI EC driver update including limited _DEP support (Lan Tianyu, Lv Zheng) - ACPI backlight driver update including a new mechanism to allow native backlight handling to be forced on non-Windows 8 systems and a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede) - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu) - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger, Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki) - Fixes related to suspend-to-idle for the iTCO watchdog driver and the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu) - PM tracing support for the suspend phase of system suspend/resume transitions (Zhonghui Fu) - Configurable delay for the system suspend/resume testing facility (Brian Norris) - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)" * tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits) ACPI / scan: Fix NULL pointer dereference in acpi_companion_match() ACPI / scan: Rework modalias creation when "compatible" is present intel_idle: mark cpu id array as __initconst powercap / RAPL: mark rapl_ids array as __initconst powercap / RAPL: add ID for Broadwell server intel_pstate: Knights Landing support intel_pstate: remove MSR test cpufreq: fix qoriq uniprocessor build ACPI / scan: Take the PRP0001 position in the list of IDs into account ACPI / scan: Simplify acpi_match_device() ACPI / scan: Generalize of_compatible matching device property: Introduce firmware node type for platform data device property: Make it possible to use secondary firmware nodes PM / watchdog: iTCO: stop watchdog during system suspend cpufreq: hisilicon: add acpu driver ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler cpufreq: powernv: Report cpu frequency throttling intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs intel_idle: Update support for Silvermont Core in Baytrail SOC PM / devfreq: tegra: Register governor on module init ...
2015-03-25driver core: Make probe deferral more quietMark Brown
Currently probe deferral prints a message every time a device requests deferral at info severity (which is displayed by default). This can have an impact on system boot times with serial consoles and is generally quite noisy. Since subsystems and drivers should already be logging the specific reason for probe deferral in order to aid users in understanding problems the messages from the driver core should be redundant lower the severity of the messages printed, cutting down on the volume of output on the console. This does mean that if the drivers and subsystems aren't doing a good job we get no output on the console by default. Ideally we'd be able to arrange to print if nothing else printed, though that's a little fun. Even better would be to come up with a mechanism that explicitly does dependencies so we don't have to keep polling and erroring. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25driver core: use *switch* statement in really_probe()Sergei Shtylyov
There are series of comparisons of the 'ret' variable on the failure path of really_probe(), so the *switch* statement seems more appropriate there. Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-22driver core / PM: Add PM domain callbacks for device setup/cleanupRafael J. Wysocki
If PM domains are in use, it may be necessary to prepare the code handling a PM domain for driver probing. For example, in some cases device drivers rely on the ability to power on the devices with the help of the IO runtime PM framework and the PM domain code needs to be ready for that. Also, if that code has not been fully initialized yet, the driver probing should be deferred. Moreover, after the probing is complete, it may be necessary to put the PM domain in question into the state reflecting the current needs of the devices in it, for example, so that power is not drawn in vain. The same should be done after removing a driver from a device, as the PM domain state may need to be changed to reflect the new situation. For these reasons, introduce new PM domain callbacks, ->activate, ->sync and ->dismiss called, respectively, before probing for a device driver, after the probing has completed successfully and if the probing has failed or the driver has been removed. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23driver core: Remove kerneldoc from local functionThierry Reding
The deferred_probe_work_func() function is locally scoped, therefore an associated kerneldoc comment isn't very useful. Replace the kerneldoc opening marker (/**) with a regular block comment marker (/*) to avoid the comment from being parsed by kerneldoc. This gets rid of a warning caused by a missing description for the "work" argument. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27driver core: Inline dev_set/get_drvdataJean Delvare
dev_set_drvdata and dev_get_drvdata are now simple enough again that we can inline them as they used to be before commit b40284378. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27driver core: dev_get_drvdata: Don't check for NULL devJean Delvare
There is no point in calling dev_get_drvdata without a valid device. So checking for dev == NULL is pointless. If such a check is ever needed - which I doubt - the driver should do it before calling dev_get_drvdata. We were returning NULL if dev was NULL, which the caller certainly did not expect anyway, so that was only delaying the crash if the caller is not paying attention. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27driver core: dev_set_drvdata returns voidJean Delvare
dev_set_drvdata can no longer fail, so it could return void. All callers have hopefully been updated to no longer check for the return value. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27driver core: Move driver_data back to struct deviceJean Delvare
Having to allocate memory as part of dev_set_drvdata() is a problem because that memory may never get freed if the device itself is not created. So move driver_data back to struct device. This is a partial revert of commit b4028437. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-29drivercore: deferral race condition fixGrant Likely
When the kernel is built with CONFIG_PREEMPT it is possible to reach a state when all modules loaded but some driver still stuck in the deferred list and there is a need for external event to kick the deferred queue to probe these drivers. The issue has been observed on embedded systems with CONFIG_PREEMPT enabled, audio support built as modules and using nfsroot for root filesystem. The following log fragment shows such sequence when all audio modules were loaded but the sound card is not present since the machine driver has failed to probe due to missing dependency during it's probe. The board is am335x-evmsk (McASP<->tlv320aic3106 codec) with davinci-evm machine driver: ... [ 12.615118] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: ENTER [ 12.719969] davinci_evm sound.3: davinci_evm_probe: ENTER [ 12.725753] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card [ 12.753846] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component [ 12.922051] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component DONE [ 12.950839] davinci_evm sound.3: ASoC: platform (null) not registered [ 12.957898] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card DONE (-517) [ 13.099026] davinci-mcasp 4803c000.mcasp: Kicking the deferred list [ 13.177838] davinci-mcasp 4803c000.mcasp: really_probe: probe_count = 2 [ 13.194130] davinci_evm sound.3: snd_soc_register_card failed (-517) [ 13.346755] davinci_mcasp_driver_init: LEAVE [ 13.377446] platform sound.3: Driver davinci_evm requests probe deferral [ 13.592527] platform sound.3: really_probe: probe_count = 0 In the log the machine driver enters it's probe at 12.719969 (this point it has been removed from the deferred lists). McASP driver already executing it's probing (since 12.615118). The machine driver tries to construct the sound card (12.950839) but did not found one of the components so it fails. After this McASP driver registers all the ASoC components (the machine driver still in it's probe function after it failed to construct the card) and the deferred work is prepared at 13.099026 (note that this time the machine driver is not in the lists so it is not going to be handled when the work is executing). Lastly the machine driver exit from it's probe and the core places it to the deferred list but there will be no other driver going to load and the deferred queue is not going to be kicked again - till we have external event like connecting USB stick, etc. The proposed solution is to try the deferred queue once more when the last driver is asking for deferring and we had drivers loaded while this last driver was probing. This way we can avoid drivers stuck in the deferred queue. Signed-off-by: Grant Likely <grant.likely@linaro.org> Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Brown <broonie@kernel.org> Cc: Stable <stable@vger.kernel.org> # v3.4+
2014-04-16drivers/base/dd.c incorrect pr_debug() parametersFrank Rowand
pr_debug() parameters are reverse order of format string Signed-off-by: Frank Rowand <frank.rowand@sonymobile.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-07PM / runtime: Use pm_runtime_put_sync() in __device_release_driver()Rafael J. Wysocki
Commit fa180eb448fa (PM / Runtime: Idle devices asynchronously after probe|release) modified __device_release_driver() to call pm_runtime_put(dev) instead of pm_runtime_put_sync(dev) before detaching the driver from the device. However, that was a mistake, because pm_runtime_put(dev) causes rpm_idle() to be queued up and the driver may be gone already when that function is executed. That breaks the assumptions the drivers have the right to make about the core's behavior on the basis of the existing documentation and actually causes problems to happen, so revert that part of commit fa180eb448fa and restore the previous behavior of __device_release_driver(). Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Fixes: fa180eb448fa (PM / Runtime: Idle devices asynchronously after probe|release) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Kevin Hilman <khilman@linaro.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
2013-04-11PM / Runtime: Idle devices asynchronously after probe|releaseUlf Hansson
Putting devices into idle|suspend in a synchronous manner means we are waiting for each device to become idle|suspended before the probe|release is fully done. This patch switch to use the asynchronous runtime PM API:s instead and thus improves the parallelism since we can move on and handle the next device in queue in an earlier phase. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Kevin Hilman <khilman@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Alan Stern <stern@rowland.harvard.edu> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-21Merge tag 'driver-core-3.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core patches from Greg Kroah-Hartman: "Here is the big driver core merge for 3.9-rc1 There are two major series here, both of which touch lots of drivers all over the kernel, and will cause you some merge conflicts: - add a new function called devm_ioremap_resource() to properly be able to check return values. - remove CONFIG_EXPERIMENTAL Other than those patches, there's not much here, some minor fixes and updates" Fix up trivial conflicts * tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (221 commits) base: memory: fix soft/hard_offline_page permissions drivercore: Fix ordering between deferred_probe and exiting initcalls backlight: fix class_find_device() arguments TTY: mark tty_get_device call with the proper const values driver-core: constify data for class_find_device() firmware: Ignore abort check when no user-helper is used firmware: Reduce ifdef CONFIG_FW_LOADER_USER_HELPER firmware: Make user-mode helper optional firmware: Refactoring for splitting user-mode helper code Driver core: treat unregistered bus_types as having no devices watchdog: Convert to devm_ioremap_resource() thermal: Convert to devm_ioremap_resource() spi: Convert to devm_ioremap_resource() power: Convert to devm_ioremap_resource() mtd: Convert to devm_ioremap_resource() mmc: Convert to devm_ioremap_resource() mfd: Convert to devm_ioremap_resource() media: Convert to devm_ioremap_resource() iommu: Convert to devm_ioremap_resource() drm: Convert to devm_ioremap_resource() ...
2013-02-15drivercore: Fix ordering between deferred_probe and exiting initcallsGrant Likely
One of the side effects of deferred probe is that some drivers which used to be probed before initcalls completed are now happening slightly later. This causes two problems. - If a console driver gets deferred, then it may not be ready when userspace starts. For example, if a uart depends on pinctrl, then the uart will get deferred and /dev/console will not be available - __init sections will be discarded before built-in drivers are probed. Strictly speaking, __init functions should not be called in a drivers __probe path, but there are a lot of drivers (console stuff again) that do anyway. In the past it was perfectly safe to do so because all built-in drivers got probed before the end of initcalls. This patch fixes the problem by forcing the first pass of the deferred list to complete at late_initcall time. This is late enough to catch the drivers that are known to have the above issues. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Tested-by: Haojian Zhuang <haojian.zhuang@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable <stable@vger.kernel.org> # 3.4+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-23drivers/pinctrl: grab default handles from device coreLinus Walleij
This makes the device core auto-grab the pinctrl handle and set the "default" (PINCTRL_STATE_DEFAULT) state for every device that is present in the device model right before probe. This will account for the lion's share of embedded silicon devcies. A modification of the semantics for pinctrl_get() is also done: previously if the pinctrl handle for a certain device was already taken, the pinctrl core would return an error. Now, since the core may have already default-grabbed the handle and set its state to "default", if the handle was already taken, this will be disregarded and the located, previously instanitated handle will be returned to the caller. This way all code in drivers explicitly requesting their pinctrl handlers will still be functional, and drivers that want to explicitly retrieve and switch their handles can still do that. But if the desired functionality is just boilerplate of this type in the probe() function: struct pinctrl *p; p = devm_pinctrl_get_select_default(&dev); if (IS_ERR(p)) { if (PTR_ERR(p) == -EPROBE_DEFER) return -EPROBE_DEFER; dev_warn(&dev, "no pinctrl handle\n"); } The discussion began with the addition of such boilerplate to the omap4 keypad driver: http://marc.info/?l=linux-input&m=135091157719300&w=2 A previous approach using notifiers was discussed: http://marc.info/?l=linux-kernel&m=135263661110528&w=2 This failed because it could not handle deferred probes. This patch alone does not solve the entire dilemma faced: whether code should be distributed into the drivers or if it should be centralized to e.g. a PM domain. But it solves the immediate issue of the addition of boilerplate to a lot of drivers that just want to grab the default state. As mentioned, they can later explicitly retrieve the handle and set different states, and this could as well be done by e.g. PM domains as it is only related to a certain struct device * pointer. ChangeLog v4->v5 (Stephen): - Simplified the devicecore grab code. - Deleted a piece of documentation recommending that pins be mapped to a device rather than hogged. ChangeLog v3->v4 (Linus): - Drop overzealous NULL checks. - Move kref initialization to pinctrl_create(). - Seeking Tested-by from Stephen Warren so we do not disturb the Tegra platform. - Seeking ACK on this from Greg (and others who like it) so I can merge it through the pinctrl subsystem. ChangeLog v2->v3 (Linus): - Abstain from using IS_ERR_OR_NULL() in the driver core, Russell recently sent a patch to remove it. Handle the NULL case explicitly even though it's a bogus case. - Make sure we handle probe deferral correctly in the device core file. devm_kfree() the container on error so we don't waste memory for devices without pinctrl handles. - Introduce reference counting into the pinctrl core using <linux/kref.h> so that we don't release pinctrl handles that have been obtained for two or more places. ChangeLog v1->v2 (Linus): - Only store a pointer in the device struct, and only allocate this if it's really used by the device. Cc: Felipe Balbi <balbi@ti.com> Cc: Benoit Cousson <b-cousson@ti.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Mitch Bradley <wmb@firmworks.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Rickard Andersson <rickard.andersson@stericsson.com> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> [swarren: fixed and simplified error-handling in pinctrl_bind_pins(), to correctly handle deferred probe. Removed admonition from docs not to use pinctrl hogs for devices] Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-07-16PM / Runtime: Do not increment device usage counts before probingRafael J. Wysocki
The pm_runtime_get_noresume() calls before really_probe() and before executing __device_attach() for each driver on the device's bus cause problems to happen if probing fails and if the driver has enabled runtime PM for the device in its .probe() callback. Namely, in that case, if the device has been resumed by the driver after enabling its runtime PM and if it turns out that .probe() should return an error, the driver is supposed to suspend the device and disable its runtime PM before exiting .probe(). However, because the device's runtime PM usage counter was incremented by the core before calling .probe(), the driver's attempt to suspend the device will not succeed and the device will remain in the full-power state after the failing .probe() has returned. To fix this issue, remove the pm_runtime_get_noresume() calls from driver_probe_device() and from device_attach() and replace the corresponding pm_runtime_put_sync() calls with pm_runtime_idle() to preserve the existing behavior (which is to check if the device is idle and to suspend it eventually in that case after probing). Reported-and-tested-by: Kevin Hilman <khilman@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16driver core: Move deferred devices to the end of dpm_list before probingMark Brown
When deferred probe was originally added the idea was that devices which defer their probes would move themselves to the end of dpm_list in order to try to keep the assumptions that we're making about the list being in roughly the order things should be suspended correct. However this hasn't been what's been happening and doing it requires a lot of duplicated code to do the moves. Instead take a simple, brute force solution and have the deferred probe code push devices to the end of dpm_list before it retries the probe. This does mean we lock the dpm_list a bit more often but it's very simple and the code shouldn't be a fast path. We do the move with the deferred mutex dropped since doing things with fewer locks held simultaneously seems like a good idea. This approach was most recently suggested by Grant Likely. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Grant Likely <grant.likely@secretlab.ca>, Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-05Merge v3.5-rc5 into driver-core-nextGreg Kroah-Hartman
This picks up the big printk fixes, and resolves a merge issue with: drivers/extcon/extcon_gpio.c Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13device-core: Ensure drvdata = NULL when no driver is boundHans de Goede
1) drvdata is for a driver to store a pointer to driver specific data 2) If no driver is bound, there is no driver specific data associated with the device 3) Thus logically drvdata should be NULL if no driver is bound. But many drivers don't clear drvdata on device_release, or set drvdata early on in probe and leave it set on probe error. Both of which results in a dangling pointer in drvdata. This patch enforce for drvdata to be NULL after device_release or on probe failure. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>