linux.git/drivers/acpi/ec.c, branch v3.15

ACPI / EC: Process rather than discard events in acpi_ec_clear

2014-04-29T21:07:38+00:00

Address a regression caused by commit ad332c8a4533:
(ACPI / EC: Clear stale EC events on Samsung systems)

After the earlier patch, there was found to be a race condition on some
earlier Samsung systems (N150/N210/N220). The function acpi_ec_clear was
sometimes discarding a new EC event before its GPE was triggered by the
system. In the case of these systems, this meant that the "lid open"
event was not registered on resume if that was the cause of the wake,
leading to problems when attempting to close the lid to suspend again.

After testing on a number of Samsung systems, both those affected by the
previous EC bug and those affected by the race condition, it seemed that
the best course of action was to process rather than discard the events.
On Samsung systems which accumulate stale EC events, there does not seem
to be any adverse side-effects of running the associated _Q methods.

This patch adds an argument to the static function acpi_ec_sync_query so
that it may be used within the acpi_ec_clear loop in place of
acpi_ec_query_unlocked which was used previously.

With thanks to Stefan Biereigel for reporting the issue, and for all the
people who helped test the new patch on affected systems.

Fixes: ad332c8a4533 (ACPI / EC: Clear stale EC events on Samsung systems)
References: https://lkml.kernel.org/r/532FE3B2.9060808@biereigel-wb.de
References: https://bugzilla.kernel.org/show_bug.cgi?id=44161#c173
Reported-by: Stefan Biereigel 
Signed-off-by: Kieran Clancy 
Tested-by: Stefan Biereigel 
Tested-by: Dennis Jansen 
Tested-by: Nicolas Porcel 
Tested-by: Maurizio D'Addona 
Tested-by: Juan Manuel Cabo 
Tested-by: Giannis Koutsou 
Tested-by: Kieran Clancy 
Cc: 3.14+  # 3.14+
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Clear stale EC events on Samsung systems

2014-03-06T12:27:23+00:00

A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc)
continue to log events during sleep (lid open/close, AC plug/unplug,
battery level change), which accumulate in the EC until a buffer fills.
After the buffer is full (tests suggest it holds 8 events), GPEs stop
being triggered for new events. This state persists on wake or even on
power cycle, and prevents new events from being registered until the EC
is manually polled.

This is the root cause of a number of bugs, including AC not being
detected properly, lid close not triggering suspend, and low ambient
light not triggering the keyboard backlight. The bug also seemed to be
responsible for performance issues on at least one user's machine.

Juan Manuel Cabo found the cause of bug and the workaround of polling
the EC manually on wake.

The loop which clears the stale events is based on an earlier patch by
Lan Tianyu (see referenced attachment).

This patch:
 - Adds a function acpi_ec_clear() which polls the EC for stale _Q
   events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is
   logged if this limit is reached.
 - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI
   system vendor is Samsung. This check could be replaced by several
   more specific DMI vendor/product pairs, but it's likely that the bug
   affects more Samsung products than just the five series mentioned
   above. Further, it should not be harmful to run acpi_ec_clear() on
   systems without the bug; it will return immediately after finding no
   data waiting.
 - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add()
 - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions()

References: https://bugzilla.kernel.org/show_bug.cgi?id=44161
References: https://bugzilla.kernel.org/show_bug.cgi?id=45461
References: https://bugzilla.kernel.org/show_bug.cgi?id=57271
References: https://bugzilla.kernel.org/attachment.cgi?id=126801
Suggested-by: Juan Manuel Cabo 
Signed-off-by: Kieran Clancy 
Reviewed-by: Lan Tianyu 
Reviewed-by: Dennis Jansen 
Tested-by: Kieran Clancy 
Tested-by: Juan Manuel Cabo 
Tested-by: Dennis Jansen 
Tested-by: Maurizio D'Addona 
Tested-by: San Zamoyski 
Cc: All applicable 
Signed-off-by: Rafael J. Wysocki

Merge branches 'acpi-gpe', 'acpi-video', 'acpi-thermal', 'acpi-processor', 'acpi-sleep'

2014-01-12T22:46:55+00:00

* acpi-gpe:
  ACPI / EC: disable GPE before removing GPE handler
  ACPI / Button: Fix enabling button GPEs twice

* acpi-video:
  ACPI: Blacklist Win8 OSI for some HP laptop 2013 models
  ACPI / video: Fix typo in video_detect.c

* acpi-thermal:
  ACPI / thermal: remove const from thermal_zone_device_ops declaration

* acpi-processor:
  ACPI / scan: bail out early if failed to parse APIC ID for CPU

* acpi-sleep:
  ACPI / sleep: remove panic in case hardware has changed after S4

ACPI / EC: Remove unused functions and add prototype declaration in internal.h

2014-01-05T23:13:23+00:00

Adds the prototype declarations of functions acpi_ec_add_query_handler()
and acpi_ec_remove_query_handler() in header file internal.h and removes
unused functions ec_burst_enable() and ec_burst_disable() in ec.c.

This eliminates the following warnings in ec.c:
drivers/acpi/ec.c:393:5: warning: no previous prototype for ‘ec_burst_enable’ [-Wmissing-prototypes]
drivers/acpi/ec.c:402:5: warning: no previous prototype for ‘ec_burst_disable’ [-Wmissing-prototypes]
drivers/acpi/ec.c:531:5: warning: no previous prototype for ‘acpi_ec_add_query_handler’ [-Wmissing-prototypes]
drivers/acpi/ec.c:552:6: warning: no previous prototype for ‘acpi_ec_remove_query_handler’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria 
Reviewed-by: Josh Triplett 
Signed-off-by: Rafael J. Wysocki

ACPI / EC: disable GPE before removing GPE handler

2013-12-19T14:56:15+00:00

Adjust the order of disabling the EC GPE and removing its handler to
avoid unhandled events.

Signed-off-by: Lan Tianyu 
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki

ACPI: Clean up inclusions of ACPI header files

2013-12-07T00:03:14+00:00

Replace direct inclusions of ,  and
, which are incorrect, with 
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, ,  and 
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds.  For CONFIG_ACPI set,
 includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.

Second, there are ordering dependencies between those files that always
have to be met.  Namely, it is required that  be included
prior to  so that the acpi_pci_root declarations the
latter depends on are always there.  And  which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds.  That also is taken care of including
 as appropriate.

Signed-off-by: Lv Zheng 
Cc: Greg Kroah-Hartman 
Cc: Matthew Garrett 
Cc: Tony Luck 
Cc: "H. Peter Anvin" 
Acked-by: Bjorn Helgaas  (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk  (Xen stuff)
Signed-off-by: Rafael J. Wysocki

Merge branch 'acpi-ec'

2013-11-19T00:06:06+00:00

* acpi-ec:
  ACPI / EC: Ensure lock is acquired before accessing ec struct members

ACPI / EC: Ensure lock is acquired before accessing ec struct members

2013-11-15T22:18:27+00:00

A bug was introduced by commit b76b51ba0cef ('ACPI / EC: Add more debug
info and trivial code cleanup') that erroneously caused the struct member
to be accessed before acquiring the required lock.  This change fixes
it by ensuring the lock acquisition is done first.

Found by Aaron Durbin 

Fixes: b76b51ba0cef ('ACPI / EC: Add more debug info and trivial code cleanup')
References: http://crbug.com/319019
Signed-off-by: Puneet Kumar 
Reviewed-by: Aaron Durbin 
[olof: Commit message reworded a bit]
Signed-off-by: Olof Johansson 
Cc: 3.8+  # 3.8+
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Convert all printk() calls to dynamic debug function

2013-09-25T15:13:50+00:00

This patch is to convert all printks in the ec driver to pr_debug/info/err
and define pr_fmt macro to replace PREFIX.

Signed-off-by: Lan Tianyu 
Signed-off-by: Rafael J. Wysocki

Merge branch 'acpi-assorted'

2013-08-30T12:13:50+00:00

* acpi-assorted:
  ACPI / EC: Add ASUSTEK L4R to quirk list in order to validate ECDT
  ACPI / thermal: Add check of "_TZD" availability and evaluating result