ACPI / PM: Ignore wakeup setting if the ACPI companion can't wake up
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 19 Nov 2014 00:44:11 +0000 (01:44 +0100)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Thu, 20 Nov 2014 00:24:16 +0000 (01:24 +0100)
As reported by Dmitry, on some Chromebooks there are devices with
corresponding ACPI objects and with unusual system wakeup
configuration.  Namely, they technically are wakeup-capable, but the
wakeup is handled via a platform-specific out-of-band mechanism and
the ACPI PM layer has no information on the wakeup capability.  As
a result, device_may_wakeup(dev) called from acpi_dev_suspend_late()
returns 'true' for those devices, but the wakeup.flags.valid flag is
unset for the corresponding ACPI device objects, so acpi_device_wakeup()
reproducibly fails for them causing acpi_dev_suspend_late() to return
an error code.  The entire system suspend is then aborted and the
machines in question cannot suspend at all.

Address the problem by ignoring the device_may_wakeup(dev) return
value in acpi_dev_suspend_late() if the ACPI companion of the device
being handled has wakeup.flags.valid unset (in which case it is clear
that the wakeup is supposed to be handled by other means).

This fixes a regression introduced by commit a76e9bd89ae7 (i2c:
attach/detach I2C client device to the ACPI power domain) as the
affected systems could suspend and resume successfully before that
commit.

Fixes: a76e9bd89ae7 (i2c: attach/detach I2C client device to the ACPI power domain)
Reported-by: Dmitry Torokhov <dtor@chromium.org>
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/acpi/device_pm.c

index 143ec6ea1468109a745bce176b2f15d3aaaced19..7db19316076659b493ab1d1c9a295dc88450381d 100644 (file)
@@ -878,7 +878,7 @@ int acpi_dev_suspend_late(struct device *dev)
                return 0;
 
        target_state = acpi_target_system_state();
-       wakeup = device_may_wakeup(dev);
+       wakeup = device_may_wakeup(dev) && acpi_device_can_wakeup(adev);
        error = acpi_device_wakeup(adev, target_state, wakeup);
        if (wakeup && error)
                return error;