Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [Medium] drm/panfrost: Spurious drm_WARN_ON during GPU reset with active perfcnt --
commit d9ae50cec3ff06c2a614193efb813114ed5ac709 Author: Boris Brezillon <[email protected]> Date: Thu Oct 15 18:22:31 2026 +0000 drm/panfrost: Enable cycle counting when perfcnt is enabled If we don't do that, we end up with invalid timestamps in the block headers. > diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c > b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c > index a9def452d5ef9..b26da057a1a01 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c > +++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c [ ... ] > @@ -84,6 +86,7 @@ static int panfrost_perfcnt_hw_enable(struct > panfrost_device *pfdev) > return ret; > > perfcnt->owns_as_ref = true; > + panfrost_cycle_counter_get(pfdev); [Severity: Medium] Will this cause a spurious drm_WARN_ON() during a GPU reset? When a GPU reset is triggered (e.g. by a job timeout), panfrost_device_reset() is called. This function calls panfrost_gpu_soft_reset() before it handles the perfcnt state via panfrost_perfcnt_reset(): drivers/gpu/drm/panfrost/panfrost_device.c:panfrost_device_reset() { ... panfrost_gpu_soft_reset(pfdev); ... panfrost_perfcnt_reset(pfdev); } Inside panfrost_gpu_soft_reset(), it expects all cycle counter references to be released: drivers/gpu/drm/panfrost/panfrost_gpu.c:panfrost_gpu_soft_reset() { ... /* * All in-flight jobs should have released their cycle * counter references upon reset, but let us make sure */ if (drm_WARN_ON(&pfdev->base, atomic_read(&pfdev->cycle_counter.use_count) != 0)) atomic_set(&pfdev->cycle_counter.use_count, 0); ... } Because the perfcnt still holds the reference when panfrost_gpu_soft_reset() is called, won't this trigger the drm_WARN_ON() and potentially panic the kernel if panic_on_warn is enabled? > > as = ret; > cfg = GPU_PERFCNT_CFG_AS(as) | -- Sashiko AI review · https://sashiko.dev/#/patchset/20261015-panfrost-reset-races-fixes-v1-0-bb74c1786...@collabora.com?part=1
