GuC to host communication is interrupt driven, the handling has 3 parts: interrupt context, tasklet and request queue worker. During GuC reset prepare, interrupt is disabled before destroy contexts steps start. The IRQ and worker are flushed to finish any outstanding in-progress message handling. But, the tasklet flush is missing, it might causes 2 race conditions: 1. Tasklet runs after IRQ flushed, add request to queue after worker flush started, causes unexpected G2H message request processing, meanwhile, reset prepare code already get the context destroyed. This will causes error reported about bad context state. (https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11349 and https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12303) 2. Tasklet runs after intel_guc_submission_reset_prepare, ct_try_receive_message start to run, while intel_uc_reset_prepare already finished guc sanitize and set ct->enable to false. This will causes warning on incorrect ct->enable state. (https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12439) Add the missing tasklet flush to flush all 3 parts. Signed-off-by: Zhanjun Dong <zhanjun.dong@xxxxxxxxx> Reviewed-by: Alan Previn <alan.previn.teres.alexis@xxxxxxxxx> --- drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index 9ede6f240d79..353a9167c9a4 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -1688,6 +1688,10 @@ void intel_guc_submission_reset_prepare(struct intel_guc *guc) spin_lock_irq(guc_to_gt(guc)->irq_lock); spin_unlock_irq(guc_to_gt(guc)->irq_lock); + /* Flush tasklet */ + tasklet_disable(&guc->ct.receive_tasklet); + tasklet_enable(&guc->ct.receive_tasklet); + guc_flush_submissions(guc); guc_flush_destroyed_contexts(guc); flush_work(&guc->ct.requests.worker); -- 2.34.1
