From: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> It is possible that, by the time we run i915_drm_freeze(), delayed_resume_work was already queued but did not run yet. If it still didn't run after intel_runtime_pm_disable_interrupts(), by the time it runs it will try to change the interrupt registers with the interrupts already disabled, which will trigger a WARN. We can reliably reproduce this with the pm_rpm system-suspend test case. In order to avoid the problem, we have to flush the work before disabling the interrupts. We could also cancel the work instead of flushing it, but that would require us to put a runtime PM reference - and any other resource we may need in the future - in case the work was already queued, so I believe flushing the work is more future-proof, although less efficient. But I can also change this part if someone requests. Another thing I tried was to move the intel_suspend_gt_powersave() call to before intel_runtime_pm_disable_interrupts(), but since that function needs to be called after the interrupts are already disabled, due to dev_priv->rps.work, this strategy didn't work. Testcase: igt/pm_rpm/system-suspend Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=80517 Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> --- drivers/gpu/drm/i915/i915_drv.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index e64547e..672694b 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -524,6 +524,8 @@ static int i915_drm_freeze(struct drm_device *dev) return error; } + flush_delayed_work(&dev_priv->rps.delayed_resume_work); + intel_runtime_pm_disable_interrupts(dev); dev_priv->enable_hotplug_processing = false; -- 2.0.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
