linux/drivers/gpu
Hans de Goede ce30560c80 drm/i915: Fix false-positive assert_rpm_wakelock_held in i915_pmic_bus_access_notifier v2
assert_rpm_wakelock_held is triggered from i915_pmic_bus_access_notifier
even though it gets unregistered on (runtime) suspend, this is caused
by a race happening under the following circumstances:

intel_runtime_pm_put does:

   atomic_dec(&dev_priv->pm.wakeref_count);

   pm_runtime_mark_last_busy(kdev);
   pm_runtime_put_autosuspend(kdev);

And pm_runtime_put_autosuspend calls intel_runtime_suspend from
a workqueue, so there is ample of time between the atomic_dec() and
intel_runtime_suspend() unregistering the notifier. If the notifier
gets called in this windowd assert_rpm_wakelock_held falsely triggers
(at this point we're not runtime-suspended yet).

This commit adds disable_rpm_wakeref_asserts and
enable_rpm_wakeref_asserts calls around the
intel_uncore_forcewake_get(FORCEWAKE_ALL) call in
i915_pmic_bus_access_notifier fixing the false-positive WARN_ON.

Changes in v2:
-Reword comment explaining why disabling the wakeref asserts is
 ok and necessary

Cc: stable@vger.kernel.org
Reported-by: FKr <bugs-freedesktop@ubermail.me>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171110150301.9601-2-hdegoede@redhat.com
2017-11-15 09:54:53 +01:00
..
drm drm/i915: Fix false-positive assert_rpm_wakelock_held in i915_pmic_bus_access_notifier v2 2017-11-15 09:54:53 +01:00
host1x gpu: host1x: Fix incorrect comment for channel_request 2017-10-20 14:19:52 +02:00
ipu-v3 gpu: ipu-v3: pre: implement workaround for ERR009624 2017-10-11 12:04:24 +02:00
vga vgaarb: Factor out EFI and fallback default device selection 2017-10-18 10:04:56 +02:00
Makefile