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path: root/drivers/acpi/ec.c
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2017-01-30ACPI / EC: Use busy polling mode when GPE is not enabledLv Zheng
When GPE is not enabled, it is not efficient to use the wait polling mode as it introduces an unexpected scheduler delay. So before the GPE handler is installed, this patch uses busy polling mode for all EC(s) and the logic can be applied to non boot EC(s) during the suspend/resume process. Link: https://bugzilla.kernel.org/show_bug.cgi?id=191561 Tested-by: Jakobus Schurz <jakobus.schurz@gmail.com> Tested-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-01-30ACPI / EC: Remove old CLEAR_ON_RESUME quirkLv Zheng
IRQ polling logic has been implemented to drain the post-boot/resume EC events: 1. Triggered by the following code, invoked from acpi_ec_enable_event(): if (!test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) advance_transaction(ec); 2. Drained by the following code, invoked after acpi_ec_complete_query(): if (status & ACPI_EC_FLAG_SCI) acpi_ec_submit_query(ec); This facility is safer than the old CLEAR_ON_RESUME quirk as the CLEAR_ON_RESUME quirk sends EC query commands unconditionally. The behavior is apparently not suitable for firmware that requires QUERY_HANDSHAKE quirk. Though the QUERY_HANDSHAKE quirk isn't used now because of the improvement done in the EC transaction state machine (ec_event_clearing=QUERY), it is the proof that we cannot send EC query command unconditionally. So it's time to delete the out-dated CLEAR_ON_RESUME quirk to let the users to try the newer approach. Link: https://bugzilla.kernel.org/show_bug.cgi?id=191211 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-10ACPI / EC: Fix unused function warning when CONFIG_PM_SLEEP=nEric Biggers
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-10ACPI / EC: Fix issues related to boot_ecLv Zheng
There are issues related to the boot_ec: 1. If acpi_ec_remove() is invoked, boot_ec will also be freed, this is not expected as the boot_ec could be enumerated via ECDT. 2. Address space handler installation/unstallation lead to unexpected _REG evaluations. This patch adds acpi_is_boot_ec() check to be used to fix the above issues. However, since acpi_ec_remove() actually won't be invoked, this patch doesn't handle the reference counting of "struct acpi_ec", it only ensures the correctness of the boot_ec destruction during the boot. Link: https://bugzilla.kernel.org/show_bug.cgi?id=153511 Reported-and-tested-by: Jonh Henderson <jw.hendy@gmail.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-10ACPI / EC: Fix a gap that ECDT EC cannot handle EC eventsLv Zheng
It is possible to register _Qxx from namespace and use the ECDT EC to perform event handling. The reported bug reveals that Windows is using ECDT in this way in case the namespace EC is not present. This patch facilitates Linux to support ECDT in this way. Link: https://bugzilla.kernel.org/show_bug.cgi?id=115021 Reported-and-tested-by: Luya Tshimbalanga <luya@fedoraproject.org> Tested-by: Jonh Henderson <jw.hendy@gmail.com> Reviewed-by: Peter Wu <peter@lekensteyn.nl> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-10ACPI / EC: Fix a memory leakage issue in acpi_ec_add()Lv Zheng
When the handler installation failed, there was no code to free the allocated EC device. This patch fixes this memory leakage issue. Link: https://bugzilla.kernel.org/show_bug.cgi?id=115021 Reported-and-tested-by: Luya Tshimbalanga <luya@fedoraproject.org> Tested-by: Jonh Henderson <jw.hendy@gmail.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-10ACPI / EC: Cleanup first_ec/boot_ec codeLv Zheng
In order to support full ECDT (driving the ECDT EC after probing the namespace EC), we need to change our EC device alloc/free algorithm, ensure not to free old boot EC before qualifying new boot EC. This patch achieves this by cleaning up first_ec/boot_ec logic: 1. first_ec: used to perform transactions, so it is assigned in new acpi_ec_setup() function. 2. boot_ec: used to track early EC device, so it is assigned in new acpi_config_boot_ec() function which explictly tells the driver to save the EC device as early EC device. Link: https://bugzilla.kernel.org/show_bug.cgi?id=115021 Reported-and-tested-by: Luya Tshimbalanga <luya@fedoraproject.org> Tested-by: Jonh Henderson <jw.hendy@gmail.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / EC: Enable event freeze mode to improve event handling for suspend ↵Lv Zheng
process This patch enables the event freeze mode, flushing the EC event handling in .suspend() callback. This feature is experimental, if it is bisected out to be the cause of the real issues, please report the issues to the kernel bugzilla for further root causing and improvement. This mode eliminates useless _Qxx handling during the power saving operations, thus can help to tune the power saving operations faster. Tests show that this mode can efficiently block flooding _Qxx during the suspend process and tune the speed of the suspend faster. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Todd E Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / EC: Add PM operations to improve event handling for suspend processLv Zheng
In the original EC driver, though the event handling is not explicitly stopped, the EC driver is actually not able to handle events during the noirq stage as the EC driver is not prepared to handle the EC events in the polling mode. So if there is no advance_transaction() triggered, the EC driver couldn't notice the EC events. However, do we actually need to handle EC events during suspend/resume stage? EC events are mostly useless for the suspend/resume period (key strokes and battery/thermal updates, etc.,), and the useful ones (lid close, power/sleep button press) should have already been delivered to the OSPM to trigger the power saving operations. Thus this patch implements acpi_ec_disable_event() to be a reverse call of acpi_ec_enable_event(), with which, the EC driver is able to stop handling the EC events in a position before entering the noirq stage. Since there are actually 2 choices for us: 1. implement event handling in polling mode; 2. stop event handling before entering noirq stage. And this patch only implements the second choice using .suspend() callback. Thus this is experimental (first choice is better? or different hook position is better?). This patch finally keeps the old behavior by default and prepares a boot parameter to enable this feature. The differences of the event handling availability between the old behavior (this patch is not applied) and the new behavior (this patch is applied) are as follows: !FreezeEvents FreezeEvents before suspend Y Y suspend before EC Y Y suspend after EC Y N suspend_late Y N suspend_noirq Y (actually N) N resume_noirq Y (actually N) N resume_late Y (actually N) N resume before EC Y (actually N) N resume after EC Y Y after resume Y Y Where "actually N" means if there is no EC transactions, the EC driver is actually not able to notice the pending events. We can see that FreezeEvents is the only approach now can actually flush the EC event handling with both query commands and _Qxx evaluations flushed, other modes can only flush the EC event handling with only query commands flushed, _Qxx evaluations occurred after stopping the EC driver may end up failure due to the failure of the EC transaction carried out in the _Qxx control methods. We also can see that this feature should be able to trigger some platform notifications later than resuming other drivers. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Todd E Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / EC: Add PM operations to improve event handling for resume processLv Zheng
This patch makes 2 changes: 1. Restore old behavior Originally, EC driver stops handling both events and transactions in acpi_ec_block_transactions(), and restarts to handle transactions in acpi_ec_unblock_transactions_early(), restarts to handle both events and transactions in acpi_ec_unblock_transactions(). While currently, EC driver still stops handling both events and transactions in acpi_ec_block_transactions(), but restarts to handle both events and transactions in acpi_ec_unblock_transactions_early(). This patch tries to restore the old behavior by dropping __acpi_ec_enable_event() from acpi_unblock_transactions_early(). 2. Improve old behavior However this still cannot fix the real issue as both of the acpi_ec_unblock_xxx() functions are invoked in the noirq stage. Since the EC driver actually doesn't implement the event handling in the polling mode, re-enabling the event handling too early in the noirq stage could result in the problem that if there is no triggering source causing advance_transaction() to be invoked, pending SCI_EVT cannot be detected by the EC driver and _Qxx cannot be triggered. It actually makes sense to restart the event handling in any point during resuming after the noirq stage. Just like the boot stage where the event handling is enabled in .add(), this patch further moves acpi_ec_enable_event() to .resume(). After doing that, the following 2 functions can be combined: acpi_ec_unblock_transactions_early()/acpi_ec_unblock_transactions(). The differences of the event handling availability between the old behavior (this patch isn't applied) and the new behavior (this patch is applied) are as follows: !Applied Applied before suspend Y Y suspend before EC Y Y suspend after EC Y Y suspend_late Y Y suspend_noirq Y (actually N) Y (actually N) resume_noirq Y (actually N) Y (actually N) resume_late Y (actually N) Y (actually N) resume before EC Y (actually N) Y (actually N) resume after EC Y (actually N) Y after resume Y (actually N) Y Where "actually N" means if there is no triggering source, the EC driver is actually not able to notice the pending SCI_EVT occurred in the noirq stage. So we can clearly see that this patch has improved the situation. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Todd E Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / EC: Fix an issue that SCI_EVT cannot be detected after event is enabledLv Zheng
After enabling the EC event handling, Linux is still in the noirq stage, if there is no triggering source (EC transaction, GPE STS status), advance_transaction() will not be invoked and SCI_EVT cannot be detected. This patch adds one more triggering source after enabling the EC event handling to poll the pending SCI_EVT. Known issues: 1. Still no SCI_EVT triggering source There could still be no SCI_EVT triggering source after handling the first SCI_EVT (polled by this patch if any). Because after handling the first SCI_EVT, Linux could still be in noirq stage and there could still be no further triggering source in this stage. Then the second SCI_EVT indicated during this stage still cannot be detected by the EC driver. With this improvement applied, it is then possible to move acpi_ec_enable_event() out of the noirq stage to fix this issue (if the first SCI_EVT is handled out of the noirq stage, the follow-up SCI_EVTs should be able to trigger IRQs). Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Todd E Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / EC: Add EC_FLAGS_QUERY_ENABLED to reveal a hidden logicLv Zheng
There is a hidden logic in the EC driver: 1. During boot, EC_FLAGS_QUERY_PENDING is responsible for blocking event handling; 2. During suspend, EC_FLAGS_STARTED is responsible for blocking event handling. This patch uses a new EC_FLAGS_QUERY_ENABLED flag to make this hidden logic explicit and have code cleaned up. No functional change. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Todd E Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-17ACPI / EC: Add PM operations for suspend/resume noirq stageLv Zheng
It is reported that on some platforms, resume speed is not fast. The cause is: in noirq stage, EC driver is working in polling mode, and each state machine advancement requires a context switch. The context switch is not necessary to the EC driver's polling mode. This patch implements PM hooks to automatically switch the driver to/from the busy polling mode to eliminate the overhead caused by the context switch. This finally contributes to the tuning result: acpi_pm_finish() execution time is improved from 192ms to 6ms. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reported-and-tested-by: Todd E Brandt <todd.e.brandt@linux.intel.com> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-05Merge branches 'acpi-ec' and 'acpi-button'Rafael J. Wysocki
* acpi-ec: ACPI / EC: Work around method reentrancy limit in ACPICA for _Qxx * acpi-button: ACPI / button: remove pointer to old lid_sysfs on unbind
2016-08-04ACPI / EC: Work around method reentrancy limit in ACPICA for _QxxLv Zheng
A regression is caused by the following commit: Commit: 02b771b64b73226052d6e731a0987db3b47281e9 Subject: ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations In this commit, using system workqueue causes that the maximum parallel executions of _Qxx can exceed 255. This violates the method reentrancy limit in ACPICA and generates the following error log: ACPI Error: Method reached maximum reentrancy limit (255) (20150818/dsmethod-341) This patch creates a seperate workqueue and limits the number of parallel _Qxx evaluations down to a configurable value (can be tuned against number of online CPUs). Since EC events are handled after driver probe, we can create the workqueue in acpi_ec_init(). Fixes: 02b771b64b73 (ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations) Link: https://bugzilla.kernel.org/show_bug.cgi?id=135691 Cc: 4.3+ <stable@vger.kernel.org> # 4.3+ Reported-and-tested-by: Helen Buus <ubuntu@hbuus.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-25Merge branches 'acpi-ec', 'acpi-video', 'acpi-button' and 'acpi-thermal'Rafael J. Wysocki
* acpi-ec: ACPI / EC: Remove wrong ECDT correction quirks ACPI / EC: Cleanup boot EC code using acpi_ec_alloc() * acpi-video: ACPI / video: Dummy acpi_video_register should return error code ACPI / video: skip evaluating _DOD when it does not exist ACPI / video: Thinkpad X201 Tablet needs video_detect_force_video * acpi-button: ACPI / button: Add quirks for initial lid state notification ACPI / button: Refactor functions to eliminate redundant code ACPI / button: Remove initial lid state notification * acpi-thermal: ACPI / thermal: Remove create_workqueue()
2016-07-08ACPI / EC: Fix code ordering issue in ec_remove_handlers()Lv Zheng
There is an order issue in ec_remove_handlers() that acpi_ec_stop() is called before removing the operation region handler. That is incorrect, because the operation region handler removal triggers _REG(DISCONNECT) which may result in new EC transactions to carry out. That existing issue has been triggered by the following commit: Commit: dcf15cbded656a12335bc4151f3f75f10080a375 Subject: ACPI / EC: Fix a boot EC regresion by restoring boot EC which changed the driver to call ec_remove_handlers() after invoking _REG(CONNECT), so the issue has become visible. Fixes: dcf15cbded65 (ACPI / EC: Fix a boot EC regresion by restoring boot EC) Link: https://bugzilla.kernel.org/show_bug.cgi?id=102421 Reported-and-tested-by: Wolfram Sang <wsa@the-dreams.de> Reported-by: Nicholas <nkudriavtsev@gmail.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-04ACPI / EC: Remove wrong ECDT correction quirksLv Zheng
Our Windows probe result shows that EC._REG is evaluated after evaluating all _INI/_STA control methods. With boot EC always switched in acpi_ec_dsdt_probe(), we can see that as long as there is no EC opregion accesses in the MLC (module level code, AML code out of any control methods) and in _INI/_STA, there is no need to make sure that ECDT must be correct. Bugs of 9399/12461 were reported against an order issue that BAT0/1._STA evaluations contain EC accesses while the ECDT setting is wrong. >From the acpidump output posted on bug 9399, we can see that it is actually a different issue. In this table, if EC._REG is not executed, EC accesses will be done in a platform specific manner. As we've already ensured not to execute EC._REG during the eary stage, we can remove the quirks for bug 9399. From the acpidump output posted on bug 12461, we can see that it still needs the quirk. In this table, EC._REG flags a named object whose default value is One, thus BAT1._STA surely should invoke EC accesses whatever we invoke EC._REG or not. We have to keep the quirk for it before we can root cause the issue. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-04ACPI / EC: Cleanup boot EC code using acpi_ec_alloc()Lv Zheng
Failure handling of the boot EC code is not tidy. This patch cleans them up with acpi_ec_alloc(). This patch also changes acpi_ec_dsdt_probe(), always switches the boot EC from the ECDT one to the DSDT one in this function. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-07ACPI / EC: Fix a boot EC regresion by restoring boot EC support for the DSDT ECLv Zheng
According to the Windows probing result, during the table loading, the EC device described in the ECDT should be used. And the ECDT EC is also effective during the period the namespace objects are initialized (we can see a separate process executing _STA/_INI on Windows before executing other device specific control methods, for example, EC._REG). During the device enumration, the EC device described in the DSDT should be used. But there are differences between Linux and Windows around the device probing order. Thus in Linux, we should enable the DSDT EC as early as possible before enumerating devices in order not to trigger issues related to the device enumeration order differences. This patch thus converts acpi_boot_ec_enable() into acpi_ec_dsdt_probe() to fix the gap. This also fixes a user reported regression triggered after we switched the "table loading"/"ECDT support" to be ACPI spec 2.0 compliant. Fixes: 59f0aa9480cf (ACPI 2.0 / ECDT: Remove early namespace reference from EC) Link: https://bugzilla.kernel.org/show_bug.cgi?id=119261 Reported-and-tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-09ACPI 2.0 / ECDT: Remove early namespace reference from ECLv Zheng
All operation region accesses are allowed by AML interpreter when AML is executed, so actually BIOSen are responsible to avoid the operation region accesses in AML before OSPM has prepared an operation region driver. This is done via _REG control method. So AML code normally sets a global named object REGC to 1 when _REG(3, 1) is evaluated. Then what is ECDT? Quoting from ACPI spec 6.0, 5.2.15 Embedded Controller Boot Resources Table (ECDT): "The presence of this table allows OSPM to provide Embedded Controller operation region space access before the namespace has been evaluated." Spec also suggests a compatible mean to indicate the early EC access availability: Device (EC) { Name (REGC, Ones) Method (_REG, 2) { If (LEqual (Arg0, 3)) { Store (Arg1, REGC) } } Method (ECAV) { If (LEqual (REGC, Ones)) { If (LGreaterEqual (_REV, 2)) { Return (One) } Else { Return (Zero) } } Else { Return (REGC) } } } In this way, it allows EC accesses to happen before EC._REG(3, 1) is invoked. But ECAV is not the only way practical BIOSen using to indicate the early EC access availibility, the known variations include: 1. Setting REGC to One in \_SB._INI when _REV >= 2. Since \_SB._INI is the first control method evaluated by OSPM during the enumeration, this allows EC accesses to happen for the entire enumeration process before the namespace EC is enumerated. 2. Initialize REGC to One by default, this even allows EC accesses to happen during the table loading. Linux is now broken around ECDT support during the long term bug fixing work because it has merged many wrong ECDT bug fixes (see details below). Linux currently uses namespace EC's settings instead of ECDT settings when ECDT is detected. This apparently will result in namespace walk and _CRS/_GPE/_REG evaluations. Such stuffs could only happen after namespace is ready, while ECDT is purposely to be used before namespace is ready. The wrong bug fixing story is: 1. Link 1: At Linux ACPI early stages, "no _Lxx/_Exx/_Qxx evaluation can happen before the namespace is ready" are not ensured by ACPICA core and Linux. This is currently ensured by deferred enabling of GPE and defered registering of EC query methods (acpi_ec_register_query_methods). 2. Link 2: Reporters reported buggy ECDTs, expecting quirks for the platform. Originally, the quirk is simple, only doing things with ECDT. Bug 9399 and 12461 are platforms (Asus L4R, Asus M6R, MSI MS-171F) reported to have wrong ECDT IO port addresses, the port addresses are reversed. Bug 11880 is a platform (Asus X50GL) reported to have 0 valued port addresses, we can see that all EC accesses are protected by ECAV on this platform, so actually no early EC accesses is required by this platform. 3. Link 3: But when the bug fixing developer was requested to provide a handy and non-quirk bug fix, he tried to use correct EC settings from namespace and broke the spec purpose. We can even see that the developer was suffered from many regrssions. One interesting one is 14086, where the actual root cause obviously should be: _REG is evaluated too early. But unfortunately, the bug is fixed in a totally wrong way. So everything goes wrong from these commits: Commit: c6cb0e878446c79f42e7833d7bb69ed6bfbb381f Subject: ACPI: EC: Don't trust ECDT tables from ASUS Commit: a5032bfdd9c80e0231a6324661e123818eb46ecd Subject: ACPI: EC: Always parse EC device This patch reverts Linux behavior to simple ECDT quirk support in order to stop early _CRS/_GPE/_REG evaluations. For Bug 9399, 12461, since it is reported that the platforms require early EC accesses, this patch restores the simple ECDT quirks for them. For Bug 11880, since it is not reported that the platform requires early EC accesses and its ACPI tables contain correct ECAV, we choose an ECDT enumeration failure for this platform. Link 1: https://bugzilla.kernel.org/show_bug.cgi?id=9916 http://bugzilla.kernel.org/show_bug.cgi?id=10100 https://lkml.org/lkml/2008/2/25/282 Link 2: https://bugzilla.kernel.org/show_bug.cgi?id=9399 https://bugzilla.kernel.org/show_bug.cgi?id=12461 https://bugzilla.kernel.org/show_bug.cgi?id=11880 Link 3: https://bugzilla.kernel.org/show_bug.cgi?id=11884 https://bugzilla.kernel.org/show_bug.cgi?id=14081 https://bugzilla.kernel.org/show_bug.cgi?id=14086 https://bugzilla.kernel.org/show_bug.cgi?id=14446 Link 4: https://bugzilla.kernel.org/show_bug.cgi?id=112911 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-09ACPI 2.0 / ECDT: Split EC_FLAGS_HANDLERS_INSTALLEDLv Zheng
This patch splits EC_FLAGS_HANDLERS_INSTALLED so that address space handler can be installed when it is not possible to install GPE handler during early stage. This patch also tunes address space handler installation, making it happening earlier than GPE handler installation for the same purpose. Since acpi_ec_start()/acpi_ec_stop() will be entered multiple times after applying this change, it is also required to protect acpi_enable_gpe()/ acpi_disable_gpe() invocations. Link: https://bugzilla.kernel.org/show_bug.cgi?id=112911 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-16ACPI-EC: Drop unnecessary check made before calling acpi_ec_delete_query()Markus Elfring
The acpi_ec_delete_query() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-26ACPI / EC: Fix a race issue in acpi_ec_guard_event()Lv Zheng
In acpi_ec_guard_event(), EC transaction state machine variables should be checked with the EC spinlock locked. The bug doesn't trigger any real issue now because this bug can only occur when the ec_event_clearing=event mode is applied while there is no user currently using this mode. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-26ACPI / EC: Fix query handler related issuesLv Zheng
1. acpi_ec_remove_query_handlers() This patch refines the query handler removal logic implemented in acpi_ec_remove_query_handler(), making it to invoke new acpi_ec_remove_query_handlers() API, and ensuring all other removal code paths to invoke the new API to honor the reference count of the query handlers. 2. acpi_ec_get_query_handler_by_value() This patch also refines the query handler search logic originally implemented in acpi_ec_query(), collecting it into acpi_ec_get_query_handler_by_value(). And since schedule_work() can ensure the serilization of acpi_ec_event_handler(), we needn't put the mutex_lock() around schedule_work(). Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-26ACPI / EC: Fix a memory leak issue in acpi_ec_query()Lv Zheng
When query handler is not found, "result" is actually stil 0, and "struct acpi_ec_query" is not NULL, so the deletion code of "struct acpi_ec_query" at the end of the function cannot be invoked. As a consequence, memory leak can be observed. The issue is introduced by this commit: Commit: 02b771b64b73226052d6e731a0987db3b47281e9 Subject: ACPI / EC: Fix an issue caused by the serialized _Qxx This patch fixes such memory leakage. Fixes: 02b771b64b73 (ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations) Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-01Merge branches 'acpi-pci', 'acpi-soc', 'acpi-ec' and 'acpi-osl'Rafael J. Wysocki
* acpi-pci: ACPI, PCI: Penalize legacy IRQ used by ACPI SCI * acpi-soc: ACPI / LPSS: Ignore 10ms delay for Braswell * acpi-ec: ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations * acpi-osl: ACPI / osl: replace custom implementation of readq / writeq
2015-08-25ACPI / EC: Fix an issue caused by the serialized _Qxx evaluationsLv Zheng
It is proven that Windows evaluates _Qxx handlers in a parallel way. This patch follows this fact, splits _Qxx evaluations from the NOTIFY queue to form a separate queue, so that _Qxx evaluations can be queued up on different CPUs rather than being queued up on a CPU0 bound queue. Event handling related callbacks are also renamed and sorted in this patch. Link: https://bugzilla.kernel.org/show_bug.cgi?id=94411 Reported-and-tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-08ACPI: Remove FSF mailing addressesJarkko Nikula
There is no need to carry potentially outdated Free Software Foundation mailing address in file headers since the COPYING file includes it. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-15ACPI / EC: Fix a code coverity issue when QR_EC transactions are failed.Lv Zheng
When the QR_EC transaction fails, the EC_FLAGS_QUERY_PENDING flag prevents the event handling work queue from being scheduled again. Though there shouldn't be failed QR_EC transactions, and this gap was efficiently used for catching and learning the SCI_EVT clearing timing compliance issues, we need to fix this as we are not fully compatible with all platforms/Windows to handle SCI_EVT clearing timing correctly. Fixing this gives the EC driver the chances to recover from a state machine failure. So this patch fixes this issue. When nr_pending_queries drops to 0, it clears EC_FLAGS_QUERY_PENDING at the proper position for different modes in order to ensure that the SCI_EVT handling can proceed. In order to be clearer for future ec_event_clearing modes, all checks in this patch are written in the inclusive style, not the exclusive style. Cc: 3.16+ <stable@vger.kernel.org> # 3.16+ Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-15ACPI / EC: Fix EC_FLAGS_QUERY_HANDSHAKE platforms using new event clearing ↵Lv Zheng
timing. It is reported that on several platforms, EC firmware will not respond non-expected QR_EC (see EC_FLAGS_QUERY_HANDSHAKE, only write QR_EC when SCI_EVT is set). Unfortunately, ACPI specification doesn't define when the SCI_EVT should be cleared by the firmware, thus the original implementation queued up second QR_EC right after writing QR_EC command and before reading the returned event value as at that time the SCI_EVT is ensured not cleared. This behavior is also based on the assumption that the firmware should be able to return 0x00 to indicate "no outstanding event". This behavior did fix issues on Samsung platforms where the spurious query value of 0x00 is supported and didn't break platforms in my test queue. But recently, specific Acer, Asus, Lenovo platforms keep on blaming this change. This patch changes the behavior to re-check the SCI_EVT a bit later and removes EC_FLAGS_QUERY_HANDSHAKE quirks, hoping this is the Windows compliant EC driver behavior. In order to be robust to the possible regressions, instead of removing the quirk directly, this patch keeps the quirk code, removes the quirk users and keeps old behavior for Samsung platforms. Cc: 3.16+ <stable@vger.kernel.org> # 3.16+ Link: https://bugzilla.kernel.org/show_bug.cgi?id=94411 Link: https://bugzilla.kernel.org/show_bug.cgi?id=97381 Link: https://bugzilla.kernel.org/show_bug.cgi?id=98111 Reported-and-tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Reported-and-tested-by: Tigran Gabrielyan <tigrangab@gmail.com> Reported-and-tested-by: Adrien D <ghbdtn@openmailbox.org> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-15ACPI / EC: Add event clearing variation support.Lv Zheng
We've been suffering from the uncertainty of the SCI_EVT clearing timing. This patch implements 3 of 4 possible modes to handle SCI_EVT clearing variations. The old behavior is kept in this patch. Status: QR_EC is re-checked as early as possible after checking previous SCI_EVT. This always leads to 2 QR_EC transactions per SCI_EVT indication and the target may implement event queue which returns 0x00 indicating "no outstanding event". This is proven to be a conflict against Windows behavior, but is still kept in this patch to make the EC driver robust to the possible regressions that may occur on Samsung platforms. Query: QR_EC is re-checked after the target has handled the QR_EC query request command pushed by the host. Event: QR_EC is re-checked after the target has noticed the query event response data pulled by the host. This timing is not determined by any IRQs, so we may need to use a guard period in this mode, which may explain the existence of the ec_guard() code used by the old EC driver where the re-check timing is implemented in the similar way as this mode. Method: QR_EC is re-checked as late as possible after completing the _Qxx evaluation. The target may implement SCI_EVT like a level triggered interrupt. It is proven on kernel bugzilla 94411 that, Windows will have all _Qxx evaluations parallelized. Thus unless required by further evidences, we needn't implement this mode as it is a conflict of the _Qxx parallelism requirement. Note that, according to the reports, there are platforms that cannot be handled using the "Status" mode without enabling the EC_FLAGS_QUERY_HANDSHAKE quirk. But they can be handled with the other modes according to the tests (kernel bugzilla 97381). The following log entry can be used to confirm the differences of the 3 modes as it should appear at the different positions for the 3 modes: Command(QR_EC) unblocked Status: appearing after EC_SC(W) = 0x84 Query: appearing after EC_DATA(R) = 0xXX where XX is the event number used to determine _QXX Event: appearing after first EC_SC(R) = 0xX0 SCI_EVT=x BURST=0 CMD=0 IBF=0 OBF=0 that is next to the following log entry: Command(QR_EC) completed by hardware Link: https://bugzilla.kernel.org/show_bug.cgi?id=94411 Link: https://bugzilla.kernel.org/show_bug.cgi?id=97381 Link: https://bugzilla.kernel.org/show_bug.cgi?id=98111 Reported-and-tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Reported-and-tested-by: Tigran Gabrielyan <tigrangab@gmail.com> Reported-and-tested-by: Adrien D <ghbdtn@openmailbox.org> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-15ACPI / EC: Convert event handling work queue into loop style.Lv Zheng
During the period that a work queue is scheduled (queued up for run) but hasn't been run, second schedule_work() could fail. This may not lead to the loss of queries because QR_EC is always ensured to be submitted after the work queue has been in the running state. The event handling work queue can be changed into the loop style to allow us to control the code in a more flexible way: 1. Makes it possible to add event=0x00 termination condition in the loop. 2. Increases the thoughput of the QR_EC transactions as the 2nd+ QR_EC transactions may be handled in the same work item used for the 1st QR_EC transaction, thus the delay caused by the 2nd+ work item scheduling can be eliminated. Except the logging message changes and the throughput improvement, this patch is just a funcitonal no-op. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Tested-by: Tigran Gabrielyan <tigrangab@gmail.com> Tested-by: Adrien D <ghbdtn@openmailbox.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-15ACPI / EC: Cleanup transaction state transition.Lv Zheng
This patch collects transaction state transition code into one function. We then could have a single function to maintain transaction transition related behaviors. No functional changes. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Tested-by: Tigran Gabrielyan <tigrangab@gmail.com> Tested-by: Adrien D <ghbdtn@openmailbox.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-16ACPI / EC: Remove non-root-caused busy polling quirks.Lv Zheng
{ Update to correct 1 patch subject in the description } We have fixed a lot of race issues in the EC driver recently. The following commit introduces MSI udelay()/msleep() quirk to MSI laptops to make EC firmware working for bug 12011 without root causing any EC driver race issues: Commit: 5423a0cb3f74c16e90683f8ee1cec6c240a9556e Subject: ACPI: EC: Add delay for slow MSI controller Commit: 34ff4dbccccce54c83b1234d39b7ad9e548a75dd Subject: ACPI: EC: Separate delays for MSI hardware The following commit extends ECDT validation quirk to MSI laptops to make EC driver locating EC registers properly for bug 12461: Commit: a5032bfdd9c80e0231a6324661e123818eb46ecd Subject: ACPI: EC: Always parse EC device This is a different quirk than the MSI udelay()/msleep() quirk. This patch keeps validating ECDT for only "Micro-Star MS-171F" as reported. The following commit extends MSI udelay()/msleep() quirk to Quanta laptops to make EC firmware working for bug 20242, there is no requirement to validate ECDT for Quanta laptops: Commit: 534bc4e3d27096e2f3fc00c14a20efd597837a4f Mon Sep 17 00:00:00 2001 Subject: ACPI EC: enable MSI workaround for Quanta laptops The following commit extends MSI udelay()/msleep() quirk to Clevo laptops to make EC firmware working for bug 77431, there is no requirement to validate ECDT for Clevo laptops: Commit: 777cb382958851c88763253fe00a26529be4c0e9 Subject: ACPI / EC: Add msi quirk for Clevo W350etq All udelay()/msleep() quirks for MSI/Quanta/Clevo seem to be the wrong fixes generated without fixing the EC driver race issues. And even if it is not wrong, the guarding can be covered by the following commits in wait polling mode: Commit: 9e295ac14d6a59180beed0735e6a504c2ee87761 Subject: ACPI / EC: Reduce ec_poll() by referencing the last register access timestamp. Commit: commit in the same series Subject: ACPI / EC: Fix and clean up register access guarding logics. The only case that is not covered is the inter-transaction guarding. And there is no evidence that we need the inter-transaction guarding upon reading the noted bug entries. So it is time to remove the quirks and let the users to try again. If there is a regression, the only thing we need to do is to restore the inter-transaction guarding for the reported platforms. Link: https://bugzilla.kernel.org/show_bug.cgi?id=12011 Link: https://bugzilla.kernel.org/show_bug.cgi?id=12461 Link: https://bugzilla.kernel.org/show_bug.cgi?id=20242 Link: https://bugzilla.kernel.org/show_bug.cgi?id=77431 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-16ACPI / EC: Add module params for polling modes.Lv Zheng
We have 2 polling modes in the EC driver: 1. busy polling: originally used for the MSI quirks. udelay() is used to perform register access guarding. 2. wait polling: normal code path uses wait_event_timeout() and it can be woken up as soon as the transaction is completed in the interrupt mode. It also contains the register acces guarding logic in case the interrupt doesn't arrive and the EC driver is about to advance the transaction in task context (the polling mode). The wait polling is useful for interrupt mode to allow other tasks to use the CPU during the wait. But for the polling mode, the busy polling takes less time than the wait polling, because if no interrupt arrives, the wait polling has to wait the minimal HZ interval. We have a new use case for using the busy polling mode. Some GPIO drivers initialize PIN configuration which cause a GPIO multiplexed EC GPE to be disabled out of the GPE register's control. Busy polling mode is useful here as it takes less time than the wait polling. But the guarding logic prevents it from responding even faster. We should spinning around the EC status rather than spinning around the nop execution lasted a determined period. This patch introduces 2 module params for the polling mode switch and the guard time, so that users can use the busy polling mode without the guarding in case the guarding is not necessary. This is an example to use the 2 module params for this purpose: acpi.ec_busy_polling acpi.ec_polling_guard=0 We've tested the patch on a test platform. The platform suffers from such kind of the GPIO PIN issue. The GPIO driver resets all PIN configuration and after that, EC interrupt cannot arrive because of the multiplexing. Then the platform suffers from a long delay carried out by the wait_event_timeout() as all further EC transactions will run in the polling mode. We switched the EC driver to use the busy polling mechanism instead of the wait timeout polling mechanism and the delay is still high: [ 44.283005] calling PNP0C0B:00+ @ 1305, parent: platform [ 44.417548] call PNP0C0B:00+ returned 0 after 131323 usecs And this patch can significantly reduce the delay: [ 44.502625] calling PNP0C0B:00+ @ 1308, parent: platform [ 44.503760] call PNP0C0B:00+ returned 0 after 1103 usecs Tested-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-16ACPI / EC: Fix and clean up register access guarding logics.Lv Zheng
In the polling mode, EC driver shouldn't access the EC registers too frequently. Though this statement is concluded from the non-root caused bugs (see links below), we've maintained the register access guarding logics in the current EC driver. The guarding logics can be found here and there, makes it hard to root cause real timing issues. This patch collects the guarding logics into one single function so that all hidden logics related to this can be seen clearly. The current guarding related code also has several issues: 1. Per-transaction timestamp prevents inter-transaction guarding from being implemented in the same place. We have an inter-transaction udelay() in acpi_ec_transaction_unblocked(), this logic can be merged into ec_poll() if we can use per-device timestamp. This patch completes such merge to form a new ec_guard() function and collects all guarding related hidden logics in it. One hidden logic is: there is no inter-transaction guarding performed for non MSI quirk (wait polling mode), this patch skips inter-transaction guarding before wait_event_timeout() for the wait polling mode to reveal the hidden logic. The other hidden logic is: there is msleep() inter-transaction guarding performed when the GPE storming is observed. As after merging this commit: Commit: e1d4d90fc0313d3d58cbd7912c90f8ef24df45ff Subject: ACPI / EC: Refine command storm prevention support EC_FLAGS_COMMAND_STORM is ensured to be cleared after invoking acpi_ec_transaction_unlocked(), the msleep() guard logic will never happen now. Since no one complains such change, this logic is likely added during the old times where the EC race issues are not fixed and the bugs are false root-caused to the timing issue. This patch simply removes the out-dated logic. We can restore it by stop skipping inter-transaction guarding for wait polling mode. Two different delay values are defined for msleep() and udelay() while they are merged in this patch to 550us. 2. time_after() causes additional delay in the polling mode (can only be observed in noirq suspend/resume processes where polling mode is always used) before advance_transaction() is invoked ("wait polling" log is added before wait_event_timeout()). We can see 2 wait_event_timeout() invocations. This is because time_after() ensures a ">" validation while we only need a ">=" validation here: [ 86.739909] ACPI: Waking up from system sleep state S3 [ 86.742857] ACPI : EC: 2: Increase command [ 86.742859] ACPI : EC: ***** Command(RD_EC) started ***** [ 86.742861] ACPI : EC: ===== TASK (0) ===== [ 86.742871] ACPI : EC: EC_SC(R) = 0x20 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=0 [ 86.742873] ACPI : EC: EC_SC(W) = 0x80 [ 86.742876] ACPI : EC: ***** Event started ***** [ 86.742880] ACPI : EC: ~~~~~ wait polling ~~~~~ [ 86.743972] ACPI : EC: ~~~~~ wait polling ~~~~~ [ 86.747966] ACPI : EC: ===== TASK (0) ===== [ 86.747977] ACPI : EC: EC_SC(R) = 0x20 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=0 [ 86.747978] ACPI : EC: EC_DATA(W) = 0x06 [ 86.747981] ACPI : EC: ~~~~~ wait polling ~~~~~ [ 86.751971] ACPI : EC: ~~~~~ wait polling ~~~~~ [ 86.755969] ACPI : EC: ===== TASK (0) ===== [ 86.755991] ACPI : EC: EC_SC(R) = 0x21 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=1 [ 86.755993] ACPI : EC: EC_DATA(R) = 0x03 [ 86.755994] ACPI : EC: ~~~~~ wait polling ~~~~~ [ 86.755995] ACPI : EC: ***** Command(RD_EC) stopped ***** [ 86.755996] ACPI : EC: 1: Decrease command This patch corrects this by using time_before() instead in ec_guard(): [ 54.283146] ACPI: Waking up from system sleep state S3 [ 54.285414] ACPI : EC: 2: Increase command [ 54.285415] ACPI : EC: ***** Command(RD_EC) started ***** [ 54.285416] ACPI : EC: ~~~~~ wait polling ~~~~~ [ 54.285417] ACPI : EC: ===== TASK (0) ===== [ 54.285424] ACPI : EC: EC_SC(R) = 0x20 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=0 [ 54.285425] ACPI : EC: EC_SC(W) = 0x80 [ 54.285427] ACPI : EC: ***** Event started ***** [ 54.285429] ACPI : EC: ~~~~~ wait polling ~~~~~ [ 54.287209] ACPI : EC: ===== TASK (0) ===== [ 54.287218] ACPI : EC: EC_SC(R) = 0x20 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=0 [ 54.287219] ACPI : EC: EC_DATA(W) = 0x06 [ 54.287222] ACPI : EC: ~~~~~ wait polling ~~~~~ [ 54.291190] ACPI : EC: ===== TASK (0) ===== [ 54.291210] ACPI : EC: EC_SC(R) = 0x21 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=1 [ 54.291213] ACPI : EC: EC_DATA(R) = 0x03 [ 54.291214] ACPI : EC: ~~~~~ wait polling ~~~~~ [ 54.291215] ACPI : EC: ***** Command(RD_EC) stopped ***** [ 54.291216] ACPI : EC: 1: Decrease command After cleaning up all guarding logics, we have one single function ec_guard() collecting all old, non-root-caused, hidden logics. Then we can easily tune the logics in one place to respond to the bug reports. Except the time_before() change, all other changes do not change the behavior of the EC driver. Link: https://bugzilla.kernel.org/show_bug.cgi?id=12011 Link: https://bugzilla.kernel.org/show_bug.cgi?id=20242 Link: https://bugzilla.kernel.org/show_bug.cgi?id=77431 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-16ACPI / EC: Remove irqs_disabled() check.Lv Zheng
The following commit merges polling and interrupt modes for EC driver: Commit: 2a84cb9852f52c0cd1c48bca41a8792d44ad06cc Mon Sep 17 00:00:00 2001 Subject: ACPI: EC: Merge IRQ and POLL modes The irqs_disabled() check introduced in it tries to fall into busy polling mode when the context of ec_poll() cannot sleep. Actually ec_poll() is ensured to be invoked in the contexts that can sleep (from a sysfs /sys/kernel/debug/ec/ec0/io access, or from acpi_evaluate_object(), or from acpi_ec_gpe_poller()). Without the MSI quirk, we never saw the udelay() logic invoked. Thus this check is useless and can be removed. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-16ACPI / EC: Remove storming threashold enlarging quirk.Lv Zheng
This patch removes the storming threashold enlarging quirk. After applying the following commit, we can notice that there is no no-op GPE handling invocation can be observed, thus it is unlikely that the no-op counts can exceed the storming threashold: Commit: ca37bfdfbc8d0a3ec73e4b97bb26dcfa51d515aa Subject: ACPI / EC: Fix several GPE handling issues by deploying ACPI_GPE_DISPATCH_RAW_HANDLER mode. Even when the storming happens, we have already limited its affection to the only transaction and no further transactions will be affected. This is done by this commit: Commit: e1d4d90fc0313d3d58cbd7912c90f8ef24df45ff Subject: ACPI / EC: Refine command storm prevention support So it's time to remove this quirk. Link: https://bugzilla.kernel.org/show_bug.cgi?id=45151 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-16ACPI / EC: Update acpi_ec_is_gpe_raised() with new GPE status flag.Lv Zheng
This patch updates acpi_ec_is_gpe_raised() according to the following commit: Commit: 09af8e8290deaff821ced01ea83594ee4c21e8df Subject: ACPICA: Events: Add support to return both enable/status register values for GPE and fixed event. This is actually a no-op change as both the flags are defined to a same value. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-04-22ACPI / EC: fix NULL pointer dereference in acpi_ec_remove_query_handler()Chris Bainbridge
Use list_for_each_entry_safe for iterating because handler may be freed in the loop. BUG: unable to handle kernel NULL pointer dereference at 000000000000002c IP: [<ffffffff814d69c8>] acpi_ec_put_query_handler+0x7/0x1a Call Trace: acpi_ec_remove_query_handler+0x87/0x97 acpi_smbus_hc_remove+0x2a/0x44 [sbshc] acpi_device_remove+0x7b/0x9a __device_release_driver+0x7e/0x110 driver_detach+0xb0/0xc0 bus_remove_driver+0x54/0xe0 driver_unregister+0x2b/0x60 acpi_bus_unregister_driver+0x10/0x12 acpi_smb_hc_driver_exit+0x10/0x12 [sbshc] SyS_delete_module+0x1b8/0x210 system_call_fastpath+0x12/0x6a Signed-off-by: Chris Bainbridge <chris.bainbridge@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-04-02ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handlerLan Tianyu
On some machines(E,G Mircosoft surface 3), ACPI battery depends on the EC operation region and it has _DEP method which contains EC. Current code doesn't support such devices whose dep_unmet will be not be decreased after EC opregion handler being installed. This blocks battery device to be attached with its driver. This patch is to fix the issue. Link: https://bugzilla.kernel.org/show_bug.cgi?id=90161 Reported-and-tested-by: Lompik <lompik@voila.fr> Tested-by: Valentin Lab <valentin.lab_bugzilla.kernel.org@kalysto.org> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-10ACPI / EC: Add GPE reference counting debugging messages.Lv Zheng
This patch enhances debugging with the GPE reference count messages added. This kind of log entries can be used by the platform validators to validate if there is an EC transaction broken because of firmware/driver bugs. No functional changes. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-10ACPI / EC: Cleanup logging/debugging splitter support.Lv Zheng
This patch refines logging/debugging splitter support so that when DEBUG is disabled, splitters won't be visible in the kernel logs while they are still available for developers when DEBUG is enabled. This patch also refines the splitters to mark the following handling process boundaries: +++++: boundary of driver starting/stopping boundary of IRQ storming =====: boundary of transaction advancement *****: boundary of EC command boundary of EC query #####: boundary of EC _Qxx evaluation The following 2 log entries are originally logged using pr_info() in order to be used as the boot/suspend/resume log entries for the EC device, this patch also restores them to pr_info() logging level: ACPI : EC: EC started ACPI : EC: EC stopped In this patch, one log entry around "Polling quirk" is converted into ec_dbg_raw() which doesn't contain the boundary marker. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-02-17ACPI / EC: Remove non-standard log emphasisScot Doyle
Remove unusual pr_info() visual emphasis introduced in ad479e7f47ca "ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag". Signed-off-by: Scot Doyle <lkml14@scotdoyle.com> [ rjw: Change pr_info() to pr_debug() too in those places. ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-02-11Revert "ACPI / EC: Add query flushing support"Rafael J. Wysocki
Revert commit f252cb09e1cb (ACPI / EC: Add query flushing support), because it breaks system suspend on Acer Aspire S5. The machine just hangs solid at the last stage of suspend (after taking non-boot CPUs offline). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-02-11Revert "ACPI / EC: Add GPE reference counting debugging messages"Rafael J. Wysocki
Revert commit b5bca896ef3c (ACPI / EC: Add GPE reference counting debugging messages), because it depends on commit f252cb09e1cb (ACPI / EC: Add query flushing support) which breaks system suspend on Acer Aspire S5 and needs to be reverted. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-02-06ACPI / EC: Add GPE reference counting debugging messagesLv Zheng
This patch enhances debugging with the GPE reference count messages added. No functional changes. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-02-06ACPI / EC: Add query flushing supportLv Zheng
This patch implementes the QR_EC flushing support. Grace periods are implemented from the detection of an SCI_EVT to the submission/completion of the QR_EC transaction. During this period, all EC command transactions are allowed to be submitted. Note that query periods and event periods are intentionally distiguished to allow further improvements. 1. Query period: from the detection of an SCI_EVT to the sumission of the QR_EC command. This period is used for storming prevention, as currently QR_EC is deferred to a work queue rather than directly issued from the IRQ context even there is no other transactions pending, so malicous SCI_EVT GPE can act like "level triggered" to trigger a GPE storm. We need to be prepared for this. And in the future, we may change it to be a part of the advance_transaction() where we will try QR_EC submission in appropriate positions to avoid such GPE storming. 2. Event period: from the detection of an SCI_EVT to the completion of the QR_EC command. We may extend it to the completion of _Qxx evaluation. This is actually a grace period for event flushing, but we only flush queries due to the reason stated in known issue 1. That's also why we use EC_FLAGS_EVENT_xxx. During this period, QR_EC transactions need to pass the flushable submission check. In this patch, the following flags are implemented: 1. EC_FLAGS_EVENT_ENABLED: this is derived from the old EC_FLAGS_QUERY_PENDING flag which can block SCI_EVT handlings. With this flag, the logics implemented by the original flag are extended: 1. Old logic: unless both of the flags are set, the event poller will not be scheduled, and 2. New logic: as soon as both of the flags are set, the evet poller will be scheduled. 2. EC_FLAGS_EVENT_DETECTED: this is also derived from the old EC_FLAGS_QUERY_PENDING flag which can block SCI_EVT detection. It thus can be used to indicate the storming prevention period for query submission. acpi_ec_submit_request()/acpi_ec_complete_request() are invoked to implement this period so that acpi_set_gpe() can be invoked under the "reference count > 0" condition. 3. EC_FLAGS_EVENT_PENDING: this is newly added to indicate the grace period for event flushing (query flushing for now). acpi_ec_submit_request()/acpi_ec_complete_request() are invoked to implement this period so that the flushing process can wait until the event handling (query transaction for now) to be completed. Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611 Link: https://bugzilla.kernel.org/show_bug.cgi?id=77431 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Ortwin Glück <odi@odi.ch> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-02-06ACPI / EC: Refine command storm prevention supportLv Zheng
This patch refines EC command storm prevention support. Current command storming code is wrong, when the storming condition is detected, it only flags the condition without doing anything for the current command but performing storming prevention for the follow-up commands. So: 1. The first command which suffers from the storming still suffers from storming. 2. The follow-up commands which may not suffer from the storming are unconditionally forced into the storming prevention mode. Ideally, we should only enable storm prevention immediately after detection for the current command so that the next command can try the power/performance efficient interrupt mode again. This patch improves the command storm prevention by disabling GPE right after the detection and re-enabling it right before completing the command transaction using the GPE storming prevention APIs. This thus deploys the following GPE handling model: 1. acpi_enable_gpe()/acpi_disable_gpe() for reference count changes: This set of APIs are used for EC usage reference counting. 2. acpi_set_gpe(ACPI_GPE_ENABLE)/acpi_set_gpe(ACPI_GPE_DISABLE): This set of APIs are used for preventing GPE storm. They must be invoked when the reference count > 0. Note that as the storming prevention should always happen when there is an outstanding request, or GPE enabling value will be messed up by the races. This patch also adds BUG_ON() to enforces this rule to prevent future bugs. The msleep(1) used after completing a transaction is useless now as this sounds like a guard time only useful for platforms that need the EC_FLAGS_MSI quirks while we have fixed GPE race issues using the previous raw handler mode enabling. It is kept to avoid regressions. A seperate patch which deletes EC_FLAGS_MSI quirks should take care of deleting it. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>