From: Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com
commit 4595a25443447b9542b2a5ee7961eb290e94b496 upstream.
If the GuC CTs are full and we need to stall the request submission while waiting for space, we save the stalled request and where the stall occurred; when the CTs have space again we pick up the request submission from where we left off.
If a full GT reset occurs, the state of all contexts is cleared and all non-guilty requests are unsubmitted, therefore we need to restart the stalled request submission from scratch. To make sure that we do so, clear the saved request after a reset.
Fixes note: the patch that introduced the bug is in 5.15, but no officially supported platform had GuC submission enabled by default in that kernel, so the backport to that particular version (and only that one) can potentially be skipped.
Fixes: 925dc1cf58ed ("drm/i915/guc: Implement GuC submission tasklet") Signed-off-by: Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com Cc: Matthew Brost matthew.brost@intel.com Cc: John Harrison john.c.harrison@intel.com Cc: stable@vger.kernel.org # v5.15+ Reviewed-by: John Harrison John.C.Harrison@Intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20220811210812.3239621-1-danie... (cherry picked from commit f922fbb0f2ad1fd3e3186f39c46673419e6d9281) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -4011,6 +4011,13 @@ static inline void guc_init_lrc_mapping( xa_destroy(&guc->context_lookup);
/* + * A reset might have occurred while we had a pending stalled request, + * so make sure we clean that up. + */ + guc->stalled_request = NULL; + guc->submission_stall_reason = STALL_NONE; + + /* * Some contexts might have been pinned before we enabled GuC * submission, so we need to add them to the GuC bookeeping. * Also, after a reset the of the GuC we want to make sure that the