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2007-05-01i2c: i2c stack can probe()David Brownell
One of a series of I2C infrastructure updates to support enumeration using the standard Linux driver model. This patch updates probe() and associated hotplug/coldplug support, but not remove(). Nothing yet _uses_ it to create I2C devices, so those hotplug/coldplug mechanisms will be the only externally visible change. This patch will be an overall NOP since the I2C stack doesn't yet create clients/devices except as part of binding them to legacy drivers. Some code is moved earlier in the source code, helping group more of the per-device infrastructure in one place and simplifying handling per-device attributes. Terminology being adopted: "legacy drivers" create devices (i2c_client) themselves, while "new style" ones follow the driver model (the i2c_client is handed to the probe routine). It's an either/or thing; the two models don't mix, and drivers that try mixing them won't even be registered. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c-nforce2: Add support for the MCP61 and MCP65Jean Delvare
Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Hans-Frieder Vogt <hfvogt@gmx.net>
2007-05-01i2c: Emulate SMBus block read over I2CJean Delvare
Let the I2C bus drivers emulate the SMBus Block Read and Block Process Call transactions if they wish. This requires to define a new message flag, which i2c-core will use to let the underlying I2C bus driver know that the first received byte will specify the length of the read message. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c: Rename dev_to_i2c_adapter()David Brownell
Rename dev_to_i2c_adapter() as to_i2c_adapter(), since the previous syntax was a surprising and needless difference from normal naming conventions in Linux. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c: Shrink struct i2c_clientDavid Brownell
This shrinks the size of "struct i2c_client" by 40 bytes: - Substantially shrinks the string used to identify the chip type - The "flags" don't need to be so big - Removes some internal padding It also adds kerneldoc for that struct, explaining how "name" is really a chip type identifier; it's otherwise potentially confusing. Because the I2C_NAME_SIZE symbol was abused for both i2c_client.name and for i2c_adapter.name, this needed to affect i2c_adapter too. The adapters which used that symbol now use the more-obviously-correct idiom of taking the size of that field. JD: Shorten i2c_adapter.name from 50 to 48 bytes while we're here, to avoid wasting space in padding. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c: i2c_adapter devices need no driverJean Delvare
Kill i2c_adapter_driver as it doesn't make sense and it prevents further i2c-core cleanups. i2c_adapter devices are virtual devices (ex-class devices) and as such they don't need a driver. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c: Kill i2c_adapter.class_devJean Delvare
Kill i2c_adapter.class_dev. Instead, set the class of i2c_adapter.dev to i2c_adapter_class, so that a symlink will be created for every i2c_adapter in /sys/class/i2c-adapter. The same change must be mirrored to i2c-isa as it duplicates some of the i2c-core functionalities. User-space tools and libraries might need some adjustments. In particular, libsensors from lm_sensors 2.10.3 or later is required for proper discovery of i2c adapter names after this change. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01mmc: remove old card statesPierre Ossman
Remove card states that no longer make any sense. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01MMC: Fix handling of low-voltage cardsPhilip Langdale
Fix handling of low voltage MMC cards. The latest MMC and SD specs both agree that support for low-voltage operations is indicated by bit 7 in the OCR. The MMC spec states that the low voltage range is 1.65-1.95V while the SD spec leaves the actual voltage range undefined - meaning that there is still no such thing as a low voltage SD card. However, an old Sandisk spec implied that bits 7.0 represented voltages below 2.0V in 1V or 0.5V increments, and the code was accordingly written with that expectation. This confusion meant that host drivers attempting to support the typical low voltage (1.8V) would set the wrong bits in the host OCR mask (usually bits 5 and/or 6) resulting in the the low voltage mode never being used. This change corrects the low voltage range and adds sanity checks on the reserved bits (0-6) and for SD cards that claim to support low-voltage operations. Signed-off-by: Philip Langdale <philipl@overt.org> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01libata: reimplement reset sequencingTejun Heo
libata previously depended upon waits in prereset to get resets after hotplug right for both spin up and device ready wait. This was necessary both for reliablity and speed as reset was likely to fail if initiated too early and each try usually took more than 30secs to fail. Previous patches fixed the reliability part by fixing status and SCR handling in resets. This patch remedies the speed part by improving reset sequencing. Prereset waiting timeout is adjusted to 10s because spinup wait is replaced by reset sequencing and !BSY wait is not as important as before. During boot or module loading where the drive is already fully spun up, !BSY wait succeeds immediately, so 10s should be enough in most cases. It matters after hotplugging or other error conditions, but in those cases, !BSY wait in prereset simply can't be relied upon due to the varied and weird behaviors ATA controllers and devices show. Reset is now driven by ata_eh_reset_timeouts[] table which contains timeouts for each reset try. The first reset can be softreset but the following ones are always hardreset if available. Each timeout defines deadline for the reset try. If a reset try fails, reset is retried with the next timeout till the end of the timeout table is reached. If a reset try fails before the timeout with error, libata waits till the deadline of the failed try before retrying. IOW, the timeout table defines timetable of reset tries such that the n'th try always begins at least after the sum of all previous timeouts has passed. The current timetable defines 4 tries and takes around 1 minute. @0 : First try. This should succeed most of the time during boot. @10 : 10s is enough to spin up most consumer harddrives. Give it another shot. @20 : 20s should spin up > 99% of working drives. This has 30s timeout for retarded devices needing long idleness post reset. @55 : Final try with 5s timeout just in case. The above timetable is trade off between not annoying the device too much with frequent resets and taking reasonable amount of time in most cases. Some controllers may do better with shorter timeouts while others may fare better with longer but we just can't rely upon LLD writers to test each controller with wide variety of devices using various scenarios. We need default behavior which reasonably fits most cases. I've tested the above timetable on a dozen SATA controllers and a few PATA controllers with about a dozen different drives from all major vendors and 4 different ODDs from three different vendors for both boot and hotplug (if available) cases. Boot probing is not affected unless the device is broken in which cases new code gives up on the port after a minute rather than five or nine minutes. When hotplugging, most devices get detected on the first or second try. Multi-platter drives with long spin up time which sometimes took > 40 secs with the original code, now usually comes up during the second try and at least right after the third try @20. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-05-01libata: add deadline support to prereset and reset methodsTejun Heo
Add @deadline to prereset and reset methods and make them honor it. ata_wait_ready() which directly takes @deadline is implemented to be used as the wait function. This patch is in preparation for EH timing improvements. * ata_wait_ready() never does busy sleep. It's only used from EH and no wait in EH is that urgent. This function also prints 'be patient' message automatically after 5 secs of waiting if more than 3 secs is remaining till deadline. * ata_bus_post_reset() now fails with error code if any of its wait fails. This is important because earlier reset tries will have shorter timeout than the spec requires. If a device fails to respond before the short timeout, reset should be retried with longer timeout rather than silently ignoring the device. There are three behavior differences. 1. Timeout is applied to both devices at once, not separately. This is more consistent with what the spec says. 2. When a device passes devchk but fails to become ready before deadline. Previouly, post_reset would just succeed and let device classification remove the device. New code fails the reset thus causing reset retry. After a few times, EH will give up disabling the port. 3. When slave device passes devchk but fails to become accessible (TF-wise) after reset. Original code disables dev1 after 30s timeout and continues as if the device doesn't exist, while the patched code fails reset. When this happens, new code fails reset on whole port rather than proceeding with only the primary device. If the failing device is suffering transient problems, new code retries reset which is a better behavior. If the failing device is actually broken, the net effect is identical to it, but not to the other device sharing the channel. In the previous code, reset would have succeeded after 30s thus detecting the working one. In the new code, reset fails and whole port gets disabled. IMO, it's a pathological case anyway (broken device sharing bus with working one) and doesn't really matter. * ata_bus_softreset() is changed to return error code from ata_bus_post_reset(). It used to return 0 unconditionally. * Spin up waiting is to be removed and not converted to honor deadline. * To be on the safe side, deadline is set to 40s for the time being. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-05-01MMC: Consolidate voltage definitionsPhilip Langdale
Consolidate the list of available voltages. Up until now, a separate set of defines has been used for host->vdd than that used for the OCR voltage mask values. Having two sets of defines allows them to get out of sync and the current sets are already inconsistent with one claiming to describe ranges and the other specific voltages. Only the SDHCI driver uses the host->vdd defines and it is easily fixed to use the OCR defines. Signed-off-by: Philip Langdale <philipl@overt.org> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01mmc: add bus handlerPierre Ossman
Delegate protocol handling to "bus handlers". This allows the core to just handle the task of arbitrating the bus. Initialisation and pampering of cards is now done by the different bus handlers. This design also allows MMC and SD (and later SDIO) to be more cleanly separated, allowing easier maintenance. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01mmc: Separate out protocol opsPierre Ossman
Move protocol operations and definitions into their own files in an effort to separate protocol handling and bus arbitration more clearly. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01mmc: Move core functions to subdirPierre Ossman
Create a "core" subdirectory to house the central bus handling functions. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01mmc: deprecate mmc bus topologyPierre Ossman
The classic MMC bus was defined as multi card bus system, which is reflected in the design in the MMC layer. When SD showed up, the bus topology was abandoned and a star topology (one card per host) was mandated. MMC version 4 has followed this, officially deprecating the bus topology. As we do not have any known users of the bus topology we can remove support for it. This will simplify the code and rectify some incorrect assumptions in the newer additions. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01mmc: Flush pending detects on host removalPierre Ossman
Make sure we kill of any pending detection runs when the host is removed instead of when it is freed. Also add some debugging to make sure the driver doesn't queue up more detection after it has removed the host. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01mmc: Move OCR bit definesPierre Ossman
All host drivers were #include:ing mmc/protocol.h just to get access to the OCR bit defines. Move these to host.h instead. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01mmc: add type field to cardsPierre Ossman
Split out the type of card into its own field as it hardly qualifies as a state. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01mmc: MMC sector based cardsPierre Ossman
Support for MMC 4.2 sector based cards. This tweaks the init a bit and reads a new field out of the EXT_CSD. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01tifm: layout fixes, small changes to comments and printfsAlex Dubov
Cosmetic changes to the code. Signed-off-by: Alex Dubov <oakad@yahoo.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01tifm_sd: implement software scatter-gatherAlex Dubov
It was found that delays associated with issue and completion of the commands severely limit performance of the new, fast SD cards. To alleviate this issue scatter-gather emulation in software is implemented for both dma and pio transfer modes. Non-block aligned and high memory sg entries are accounted for. Signed-off-by: Alex Dubov <oakad@yahoo.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01tifm_sd: replace command completion state machine with full checkingAlex Dubov
State machine used to to track mmc command state was found to be fragile and unreliable, making many cards unusable. The safer solution is to perform all needed checks at every card event. Signed-off-by: Alex Dubov <oakad@yahoo.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01tifm: move common device management tasks from tifm_7xx1 to tifm_coreAlex Dubov
Some details of the device management (create, add, remove) are really belong to the tifm_core, as they are not hardware specific. Signed-off-by: Alex Dubov <oakad@yahoo.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01tifm: move common adapter management tasks from tifm_7xx1 to tifm_coreAlex Dubov
Some details of the adapter management (create, add, remove) are really belong to the tifm_core, as they are not hardware specific. Signed-off-by: Alex Dubov <oakad@yahoo.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01tifm: replace per-adapter kthread with freezeable workqueueAlex Dubov
Freezeable workqueue makes sure that adapter work items (device insertions and removals) would be handled after the system is fully resumed. Previously this was achieved by explicit freezing of the kthread. Signed-off-by: Alex Dubov <oakad@yahoo.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01tifm: simplify bus match and uevent handlersAlex Dubov
Remove code duplicating the kernel functionality and clean up data structures involved in driver matching. Signed-off-by: Alex Dubov <oakad@yahoo.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01tifm: use bus methods to handle probe/remove instead of driver ones.Alex Dubov
Signed-off-by: Alex Dubov <oakad@yahoo.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01tifm: hide details of interrupt processing from socket driversAlex Dubov
Instead of passing transformed value of adapter interrupt status to socket drivers, implement two separate callbacks - one for card events and another for dma events. Signed-off-by: Alex Dubov <oakad@yahoo.com> Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01[DLM] interface for purge (2/2)David Teigland
Add code to accept purge commands from userland. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-04-30NFS: Added support to turn off the NFSv3 READDIRPLUS RPC.Steve Dickson
READDIRPLUS can be a performance hindrance when the client is working with large directories. In addition, some servers still have bugs in their implementations (e.g. Tru64 returns wrong values for the fsid). Add a mount flag to enable users to turn it off at mount time following the implementation in Apple's NFS client. Signed-off-by: Steve Dickson <steved@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30SUNRPC: remove old portmapperChuck Lever
net/sunrpc/pmap_clnt.c has been replaced by net/sunrpc/rpcb_clnt.c. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30SUNRPC: introduce rpcbind: replacement for in-kernel portmapperChuck Lever
Introduce a replacement for the in-kernel portmapper client that supports all 3 versions of the rpcbind protocol. This code is not used yet. Original code by Groupe Bull updated for the latest kernel, with multiple bug fixes. Note that rpcb_clnt.c does not yet support registering via versions 3 and 4 of the rpcbind protocol. That is planned for a later patch. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30SUNRPC: Eliminate side effects from rpc_mallocChuck Lever
Currently rpc_malloc sets req->rq_buffer internally. Make this a more generic interface: return a pointer to the new buffer (or NULL) and make the caller set req->rq_buffer and req->rq_bufsize. This looks much more like kmalloc and eliminates the side effects. To fix a potential deadlock, this patch also replaces GFP_NOFS with GFP_NOWAIT in rpc_malloc. This prevents async RPCs from sleeping outside the RPC's task scheduler while allocating their buffer. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30SUNRPC: RPC buffer size estimates are too largeChuck Lever
The RPC buffer size estimation logic in net/sunrpc/clnt.c always significantly overestimates the requirements for the buffer size. A little instrumentation demonstrated that in fact rpc_malloc was never allocating the buffer from the mempool, but almost always called kmalloc. To compute the size of the RPC buffer more precisely, split p_bufsiz into two fields; one for the argument size, and one for the result size. Then, compute the sum of the exact call and reply header sizes, and split the RPC buffer precisely between the two. That should keep almost all RPC buffers within the 2KiB buffer mempool limit. And, we can finally be rid of RPC_SLACK_SPACE! Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30NLM: Shrink the maximum request size of NLM4 requestsChuck Lever
NLM version 4 requests estimate the call and reply header sizes rather conservatively, using the very maximum size allowed in the protocol even though Linux always uses only a small fraction of the allowable space. Reduce the size of caller and lock arguments to conserve RPC buffer space while XDR encoding NLM4 arguments. Add compile-time checks to ensure the hostname string won't overflow NLM protocol maximums. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30NFS: Use pgoff_t in structures and functions that pass page cache offsetsTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30NFS: Fix a buffer overflow in the allocation of struct nfs_read/writedataTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30NFS: Fix a race when doing NFS write coalescingTrond Myklebust
Currently we do write coalescing in a very inefficient manner: one pass in generic_writepages() in order to lock the pages for writing, then one pass in nfs_flush_mapping() and/or nfs_sync_mapping_wait() in order to gather the locked pages for coalescing into RPC requests of size "wsize". In fact, it turns out there is actually a deadlock possible here since we only start I/O on the second pass. If the user signals the process while we're in nfs_sync_mapping_wait(), for instance, then we may exit before starting I/O on all the requests that have been queued up. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30NFS: Cleanup for nfs_readpages()Trond Myklebust
Do the coalescing of read requests into block sized requests at start of I/O as we scan through the pages instead of going through a second pass. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30NFS: Another cleanup of the read/write request coalescing codeTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30NFS: Cleanup the coalescing codeTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-05-01Input: gpio_keys - add support for switches (EV_SW)Roman Moravcik
Signed-off-by: Roman Moravcik <roman.moravcik@gmail.com> Signed-off-by: Paul Sokolovsky <pmiscml@gmail.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2007-05-01Merge master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6Dmitry Torokhov
Conflicts: drivers/usb/input/Makefile drivers/usb/input/gtco.c
2007-04-30pm: include EIO from errno-base.hDavid Rientjes
For backwards compatibility, call_platform_enable_wakeup() can return 0 instead of -EIO since we aren't guaranteed to have errno defined. Cc: David Brownell <david-b@pacbell.net> Signed-off-by: David Rientjes <rientjes@google.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-30Add kvasprintf()Jeremy Fitzhardinge
Add a kvasprintf() function to complement kasprintf(). No in-tree users yet, but I have some coming up. [akpm@linux-foundation.org: EXPORT it] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Keir Fraser <keir@xensource.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-30power management: force pm_ops.valid callback to be assignedJohannes Berg
This patch changes the docs and behaviour from "all states valid" to "no states valid" if no .valid callback is assigned. Users of pm_ops that only need mem sleep can assign pm_valid_only_mem without any overhead, others will require more elaborate callbacks. Now that all users of pm_ops have a .valid callback this is a safe thing to do and prevents things from getting messy again as they were before. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Pavel Machek <pavel@ucw.cz> Looks-okay-to: Rafael J. Wysocki <rjw@sisk.pl> Cc: <linux-pm@lists.linux-foundation.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-30power management: implement pm_ops.valid for everybodyJohannes Berg
Almost all users of pm_ops only support mem sleep, don't check in .valid and don't reject any others in .prepare so users can be confused if they check /sys/power/state, especially when new states are added (these would then result in s-t-r although they're supposed to be something different). This patch implements a generic pm_valid_only_mem function that is then exported for users and puts it to use in almost all existing pm_ops. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Cc: David Brownell <david-b@pacbell.net> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: linux-pm@lists.linux-foundation.org Cc: Len Brown <lenb@kernel.org> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Greg KH <greg@kroah.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-30power management: remove firmware disk modeJohannes Berg
This patch removes the firmware disk suspend mode which is the wrong approach, it is supposed to be used for implementing firmware-based disk suspend but cannot actually be used for that. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: <linux-pm@lists.linux-foundation.org> Cc: David Brownell <david-b@pacbell.net> Cc: Len Brown <lenb@kernel.org> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Greg KH <greg@kroah.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-30rework pm_ops pm_disk_mode, kill misuseJohannes Berg
This patch series cleans up some misconceptions about pm_ops. Some users of the pm_ops structure attempt to use it to stop the user from entering suspend to disk, this, however, is not possible since the user can always use "shutdown" in /sys/power/disk and then the pm_ops are never invoked. Also, platforms that don't support suspend to disk simply should not allow configuring SOFTWARE_SUSPEND (read the help text on it, it only selects suspend to disk and nothing else, all the other stuff depends on PM). The pm_ops structure is actually intended to provide a way to enter platform-defined sleep states (currently supported states are "standby" and "mem" (suspend to ram)) and additionally (if SOFTWARE_SUSPEND is configured) allows a platform to support a platform specific way to enter low-power mode once everything has been saved to disk. This is currently only used by ACPI (S4). This patch: The pm_ops.pm_disk_mode is used in totally bogus ways since nobody really seems to understand what it actually does. This patch clarifies the pm_disk_mode description. It also removes all the arm and sh users that think they can veto suspend to disk via pm_ops; not so since the user can always do echo shutdown > /sys/power/disk, they need to find a better way involving Kconfig or such. ACPI is the only user left with a non-zero pm_disk_mode. The patch also sets the default mode to shutdown again, but when a new pm_ops is registered its pm_disk_mode is selected as default, that way the default stays for ACPI where it is apparently required. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Cc: David Brownell <david-b@pacbell.net> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: <linux-pm@lists.linux-foundation.org> Cc: Len Brown <lenb@kernel.org> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Greg KH <greg@kroah.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>