[PATCH 1/2] ACPI: EC: Drop EC noirq hooks to fix a regression

[PATCH 1/2] ACPI: EC: Drop EC noirq hooks to fix a regression

[Lv Zheng]

According to the bug report, though the busy polling mode can make noirq
stages executed faster, it causes abnormal fan blowing up after a system
resume (see link #1 for a video demonstration) on Lenovo ThinkPad X1 Carbon
 - the 5th Generation. The problem can be fixed by an upgraded EC firmware.

However many reporters can also confirm that the problem can be fixed by
stopping busy polling during suspend/resume.

This patch drops noirq stage hooks so that the regression can be fixed
without upgrading the EC firmware.

Fixes: c3a696b6e8f8 ("ACPI / EC: Use busy polling mode when GPE is not enabled")
Link: https://youtu.be/9NQ9x-Jm99Q                       [#1]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196129
Reported-by: Andreas Lindhe <andreas@lindhe.io>
Tested-by: Gjorgji Jankovski <j.gjorgji@gmail.com>
Tested-by: Damjan Georgievski <gdamjan@gmail.com>
Tested-by: Fernando Chaves <nanochaves@gmail.com>
Tested-by: Tomislav Ivek <tomislav.ivek@gmail.com>
Tested-by: Denis P. <theoriginal.skullburner@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: Stable <stable@vger.kernel.org> # all applicable
---
 drivers/acpi/ec.c | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 854d428..05e4eb5 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1870,24 +1870,6 @@ int __init acpi_ec_ecdt_probe(void)
 }
 
 #ifdef CONFIG_PM_SLEEP
-static int acpi_ec_suspend_noirq(struct device *dev)
-{
-	struct acpi_ec *ec =
-		acpi_driver_data(to_acpi_device(dev));
-
-	acpi_ec_enter_noirq(ec);
-	return 0;
-}
-
-static int acpi_ec_resume_noirq(struct device *dev)
-{
-	struct acpi_ec *ec =
-		acpi_driver_data(to_acpi_device(dev));
-
-	acpi_ec_leave_noirq(ec);
-	return 0;
-}
-
 static int acpi_ec_suspend(struct device *dev)
 {
 	struct acpi_ec *ec =
@@ -1909,7 +1891,6 @@ static int acpi_ec_resume(struct device *dev)
 #endif
 
 static const struct dev_pm_ops acpi_ec_pm = {
-	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
 	SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
 };
 
-- 
2.7.4

[PATCH 2/2] ACPI: EC: Revert "ACPI / EC: Enable event freeze mode..." to fix a regression

[Lv Zheng]

On Lenovo ThinkPad X1 Carbon - the 5th Generation, enabling an earlier EC
event freezing timing causes acpitz-virtual-0 to report a stucked 48C
temparature. And with EC firmware revisioned as 1.14, without reverting
back to old EC event freezing timing, the fan still blows up after a system
resume (see comment 168 on link #1).

This reverts the culprit change so that the regression can be fixed without
upgrading the EC firmware.

Fixes: d30283057ecd ("ACPI / EC: Enable event freeze mode to improve event handling")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=191181 [#1]
Tested-by: Damjan Georgievski <gdamjan@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: Stable <stable@vger.kernel.org> # 4.9+
---
 drivers/acpi/ec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 05e4eb5..ddb01e9 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -147,7 +147,7 @@ static unsigned int ec_storm_threshold  __read_mostly = 8;
 module_param(ec_storm_threshold, uint, 0644);
 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 
-static bool ec_freeze_events __read_mostly = true;
+static bool ec_freeze_events __read_mostly = false;
 module_param(ec_freeze_events, bool, 0644);
 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 
-- 
2.7.4

Re: [PATCH 1/2] ACPI: EC: Drop EC noirq hooks to fix a regression

[Rafael J. Wysocki]

On Wednesday, July 12, 2017 11:09:09 AM Lv Zheng wrote:
> According to the bug report, though the busy polling mode can make noirq
> stages executed faster, it causes abnormal fan blowing up after a system
> resume (see link #1 for a video demonstration) on Lenovo ThinkPad X1 Carbon
>  - the 5th Generation. The problem can be fixed by an upgraded EC firmware.
> 
> However many reporters can also confirm that the problem can be fixed by
> stopping busy polling during suspend/resume.
> 
> This patch drops noirq stage hooks so that the regression can be fixed
> without upgrading the EC firmware.
> 
> Fixes: c3a696b6e8f8 ("ACPI / EC: Use busy polling mode when GPE is not enabled")
> Link: https://youtu.be/9NQ9x-Jm99Q                       [#1]
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=196129
> Reported-by: Andreas Lindhe <andreas@lindhe.io>
> Tested-by: Gjorgji Jankovski <j.gjorgji@gmail.com>
> Tested-by: Damjan Georgievski <gdamjan@gmail.com>
> Tested-by: Fernando Chaves <nanochaves@gmail.com>
> Tested-by: Tomislav Ivek <tomislav.ivek@gmail.com>
> Tested-by: Denis P. <theoriginal.skullburner@gmail.com>
> Signed-off-by: Lv Zheng <lv.zheng@intel.com>
> Cc: Stable <stable@vger.kernel.org> # all applicable

Both patches applied with some minor modifications in the changelogs.

Thanks,
Rafael