[PATCH 5.15 865/917] drm/i915/guc: Fix blocked context accounting

From: Greg Kroah-Hartman
Date: Mon Nov 15 2021 - 19:02:36 EST


From: Matthew Brost <matthew.brost@xxxxxxxxx>

commit fc30a6764a54dea42291aeb7009bef7aa2fc1cd4 upstream.

Prior to this patch the blocked context counter was cleared on
init_sched_state (used during registering a context & resets) which is
incorrect. This state needs to be persistent or the counter can read the
incorrect value resulting in scheduling never getting enabled again.

Fixes: 62eaf0ae217d ("drm/i915/guc: Support request cancellation")
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20210909164744.31249-2-matthew.brost@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -152,7 +152,7 @@ static inline void init_sched_state(stru
{
/* Only should be called from guc_lrc_desc_pin() */
atomic_set(&ce->guc_sched_state_no_lock, 0);
- ce->guc_state.sched_state = 0;
+ ce->guc_state.sched_state &= SCHED_STATE_BLOCKED_MASK;
}

static inline bool