linux-stable.git/drivers/acpi/ec.c, branch linux-3.18.y

ACPI / EC: Fix regression due to conflicting firmware behavior between Samsung and Acer.

2014-10-29T15:52:35+00:00

It is reported that Samsung laptops that need to poll events are broken by
the following commit:
 Commit 3afcf2ece453e1a8c2c6de19cdf06da3772a1b08
 Subject: ACPI / EC: Add support to disallow QR_EC to be issued when SCI_EVT isn't set

The behaviors of the 2 vendor firmwares are conflict:
 1. Acer: OSPM shouldn't issue QR_EC unless SCI_EVT is set, firmware
         automatically sets SCI_EVT as long as there is event queued up.
 2. Samsung: OSPM should issue QR_EC whatever SCI_EVT is set, firmware
            returns 0 when there is no event queued up.

This patch is a quick fix to distinguish the behaviors to make Acer
behavior only effective for Acer EC firmware so that the breakages on
Samsung EC firmware can be avoided.

Fixes: 3afcf2ece453 (ACPI / EC: Add support to disallow QR_EC to be issued ...)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161
Reported-and-tested-by: Ortwin Glück 
Signed-off-by: Lv Zheng 
Cc: 3.17+  # 3.17+
[ rjw : Subject ]
Signed-off-by: Rafael J. Wysocki

Revert "ACPI / EC: Add support to disallow QR_EC to be issued before completing previous QR_EC"

2014-10-29T15:48:33+00:00

It is reported that the following commit breaks Samsung hardware:
 Commit: 558e4736f2e1b0e6323adf7a5e4df77ed6cfc1a4.
 Subject: ACPI / EC: Add support to disallow QR_EC to be issued before
          completing previous QR_EC

Which means the Samsung behavior conflicts with the Acer behavior.

1. Samsung may behave like:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ] SCI_EVT set
                              write QR_EC
                              read event
   [ -event 1 ] SCI_EVT clear
   Without the above commit, Samsung can work:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ] SCI_EVT set
                              write QR_EC
                              CAN prepare next QR_EC as SCI_EVT=1
                              read event
   [ -event 1 ] SCI_EVT clear
                              write QR_EC
                              read event
   [ -event 2 ] SCI_EVT clear
   With the above commit, Samsung cannot work:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ] SCI_EVT set
                              write QR_EC
                              read event
   [ -event 1 ] SCI_EVT clear
                              CANNOT prepare next QR_EC as SCI_EVT=0
2. Acer may behave like:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ]
                              write QR_EC
                              read event
   [ -event 1 ] SCI_EVT clear
   [ +event 2 ] SCI_EVT set
   Without the above commit, Acer cannot work when there is only 1 event:
   [ +event 1 ] SCI_EVT set
                              write QR_EC
                              can prepared next QR_EC as SCI_EVT=1
                              read event
   [ -event 1 ] SCI_EVT clear
                              CANNOT write QR_EC as SCI_EVT=0
   With the above commit, Acer can work:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ]
                              write QR_EC
                              read event
   [ -event 1 ] SCI_EVT set
                              can prepare next QR_EC because SCI_EVT=0
                              CAN write QR_EC as SCI_EVT=1

Since Acer can also work with only the following commit applied:
 Commit: 3afcf2ece453e1a8c2c6de19cdf06da3772a1b08
 Subject: ACPI / EC: Add support to disallow QR_EC to be issued when
          SCI_EVT isn't set
commit 558e4736f2e1b0e6323adf7a5e4df77ed6cfc1a4 can be reverted.

Fixes: 558e4736f2e1 (ACPI / EC: Add support to disallow QR_EC to be issued ...)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161
Reported-and-tested-by: Ortwin Glück 
Signed-off-by: Lv Zheng 
Cc: 3.17+  # 3.17+
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Cleanup coding style.

2014-10-20T22:44:54+00:00

This patch cleans up the following coding style issues that are detected by
scripts/checkpatch.pl:
 ERROR: code indent should use tabs where possible
 ERROR: "foo * bar" should be "foo *bar"
 WARNING: Missing a blank line after declarations
 WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
 WARNING: void function return statements are not generally useful
 WARNING: else is not generally useful after a break or return
 WARNING: break is not useful after a goto or return
 WARNING: braces {} are not necessary for single statement blocks
 WARNING: line over 80 characters
 WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
No functional changes.

Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Refine event/query debugging messages.

2014-10-20T22:44:54+00:00

This patch refines event/query debugging messages to use a unified format
as commands. Developers can clearly find different processes by checking
different log seperators. No functional changes.

Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Add detailed command/query debugging information.

2014-10-20T22:44:53+00:00

Developers really don't need to translate EC commands in mind. This patch
adds detailed debugging information for the EC commands.
The address can be found in the follow-up sequential EC_DATA(W) accesses,
thus this patch also removes some of the redundant address information.

Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Enhance the logs to apply to QR_EC transactions.

2014-10-20T22:44:53+00:00

Currently some logs are applied to new transactions, but QR_EC transactions
are not included. This patch merges the code path to make the logs also
applying to the QR_EC transactions.

Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Add CPU ID to debugging messages.

2014-10-20T22:44:53+00:00

This patch adds CPU ID to the context entries' debugging output. no
functional changes.

Signed-off-by: Lv Zheng 
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Add msi quirk for Clevo W350etq

2014-09-01T23:57:56+00:00

Clevo W350etq's EC will not produce GPE interrupt some time after
booting. The ACPI notify event won't trigger when the issue takes
place. After debugging, adding msi quirk for the machine can fix
the issue. This patch is to add msi quirk for the machine.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=77431
Reported-and-tested-by: qbanin@gmail.com
Signed-off-by: Lan Tianyu 
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Add support to disallow QR_EC to be issued before completing previous QR_EC

2014-08-26T00:15:51+00:00

There is platform refusing to respond QR_EC when SCI_EVT isn't set
which is Acer Aspire V5-573G.

By disallowing QR_EC to be issued before the previous one has been
completed we are able to reduce the possibilities to trigger issues on
such platforms.

Note that this fix can only reduce the occurrence rate of this issue, but
this issue may still occur when such a platform doesn't clear SCI_EVT
before or immediately after completing the previous QR_EC transaction.
This patch cannot fix the CLEAR_ON_RESUME quirk which also relies on
the assumption that the platforms are able to respond even when SCI_EVT
isn't set.

But this patch is still useful as it can help to reduce the number of
scheduled QR_EC work items.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611
Reported-and-tested-by: Alexander Mezin 
Signed-off-by: Lv Zheng 
Cc: 3.16+  # 3.16+
Signed-off-by: Rafael J. Wysocki

ACPI / EC: Add support to disallow QR_EC to be issued when SCI_EVT isn't set

2014-08-26T00:15:47+00:00

There is a platform refusing to respond QR_EC when SCI_EVT isn't set
(Acer Aspire V5-573G).

Currently, we rely on the behaviour that the EC firmware can respond
something (for example, 0x00 to indicate "no outstanding events") to
QR_EC even when SCI_EVT is not set, but the reporter has complained
about AC/battery pluging/unpluging and video brightness change delay
on that platform.

This is because the work item that has issued QR_EC has to wait until
timeout in this case, and the _Qxx method evaluation work item queued
after QR_EC one is delayed.

It sounds reasonable to fix this issue by:
 1. Implementing SCI_EVT sanity check before issuing QR_EC in the EC
    driver's main state machine.
 2. Moving QR_EC issuing out of the work queue used by _Qxx evaluation
    to a seperate IRQ handling thread.

This patch fixes this issue using solution 1.

By disallowing QR_EC to be issued when SCI_EVT isn't set, we are able to
handle such platform in the EC driver's main state machine. This patch
enhances the state machine in this way to survive with such malfunctioning
EC firmware.

Note that this patch can also fix CLEAR_ON_RESUME quirk which also relies
on the assumption that the platforms are able to respond even when SCI_EVT
isn't set.

Fixes: c0d653412fc8 ACPI / EC: Fix race condition in ec_transaction_completed()
Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611
Reported-and-tested-by: Alexander Mezin 
Signed-off-by: Lv Zheng 
Cc: 3.16+  # 3.16+
Signed-off-by: Rafael J. Wysocki