Re: [PATCH v3 5/7] drm/xe: Do not deregister queues in TDR

[Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>]

On Tue, Nov 18, 2025 at 10:02:00AM -0800, Matthew Brost wrote:
>On Mon, Nov 17, 2025 at 10:41:52PM -0800, Niranjana Vishwanathapura wrote:
>> On Thu, Oct 16, 2025 at 01:48:24PM -0700, Matthew Brost wrote:
>> > Deregistering queues in the TDR introduces unnecessary complexity,
>> > requiring reference counting tricks to function correctly. All that's
>> > needed in the TDR is to kick the queue off the hardware, which is
>> > achieved by disabling scheduling. Queue deregistration should be handled
>> > in a single, well-defined point in the cleanup path, tied to the queue's
>> > reference count.
>> >
>>
>> Overall looks good to me.
>> But it would help if the commit text describes why this extra reference
>> taking was there before for lr jobs and why it is not needed now.
>>
>
>This patch isn't related to LR jobs, the following patch is.
>

I was talking about the set/clear_exec_queue_extra_ref() and its usage
being removed in this patchset.

>The deregistering queues in TDR was never required, and this patches
>removes that flow.
>

Ok, thanks.

Niranjana

>Matt
>
>> Niranjana
>>
>> > Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>> > ---
>> > drivers/gpu/drm/xe/xe_guc_submit.c | 57 +++---------------------------
>> > 1 file changed, 5 insertions(+), 52 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
>> > index 680696efc434..ab0f1a2d4871 100644
>> > --- a/drivers/gpu/drm/xe/xe_guc_submit.c
>> > +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
>> > @@ -69,9 +69,8 @@ exec_queue_to_guc(struct xe_exec_queue *q)
>> > #define EXEC_QUEUE_STATE_WEDGED			(1 << 8)
>> > #define EXEC_QUEUE_STATE_BANNED			(1 << 9)
>> > #define EXEC_QUEUE_STATE_CHECK_TIMEOUT		(1 << 10)
>> > -#define EXEC_QUEUE_STATE_EXTRA_REF		(1 << 11)
>> > -#define EXEC_QUEUE_STATE_PENDING_RESUME		(1 << 12)
>> > -#define EXEC_QUEUE_STATE_PENDING_TDR_EXIT	(1 << 13)
>> > +#define EXEC_QUEUE_STATE_PENDING_RESUME		(1 << 11)
>> > +#define EXEC_QUEUE_STATE_PENDING_TDR_EXIT	(1 << 12)
>> >
>> > static bool exec_queue_registered(struct xe_exec_queue *q)
>> > {
>> > @@ -218,21 +217,6 @@ static void clear_exec_queue_check_timeout(struct xe_exec_queue *q)
>> > 	atomic_and(~EXEC_QUEUE_STATE_CHECK_TIMEOUT, &q->guc->state);
>> > }
>> >
>> > -static bool exec_queue_extra_ref(struct xe_exec_queue *q)
>> > -{
>> > -	return atomic_read(&q->guc->state) & EXEC_QUEUE_STATE_EXTRA_REF;
>> > -}
>> > -
>> > -static void set_exec_queue_extra_ref(struct xe_exec_queue *q)
>> > -{
>> > -	atomic_or(EXEC_QUEUE_STATE_EXTRA_REF, &q->guc->state);
>> > -}
>> > -
>> > -static void clear_exec_queue_extra_ref(struct xe_exec_queue *q)
>> > -{
>> > -	atomic_and(~EXEC_QUEUE_STATE_EXTRA_REF, &q->guc->state);
>> > -}
>> > -
>> > static bool exec_queue_pending_resume(struct xe_exec_queue *q)
>> > {
>> > 	return atomic_read(&q->guc->state) & EXEC_QUEUE_STATE_PENDING_RESUME;
>> > @@ -1190,25 +1174,6 @@ static void disable_scheduling(struct xe_exec_queue *q, bool immediate)
>> > 		       G2H_LEN_DW_SCHED_CONTEXT_MODE_SET, 1);
>> > }
>> >
>> > -static void __deregister_exec_queue(struct xe_guc *guc, struct xe_exec_queue *q)
>> > -{
>> > -	u32 action[] = {
>> > -		XE_GUC_ACTION_DEREGISTER_CONTEXT,
>> > -		q->guc->id,
>> > -	};
>> > -
>> > -	xe_gt_assert(guc_to_gt(guc), !exec_queue_destroyed(q));
>> > -	xe_gt_assert(guc_to_gt(guc), exec_queue_registered(q));
>> > -	xe_gt_assert(guc_to_gt(guc), !exec_queue_pending_enable(q));
>> > -	xe_gt_assert(guc_to_gt(guc), !exec_queue_pending_disable(q));
>> > -
>> > -	set_exec_queue_destroyed(q);
>> > -	trace_xe_exec_queue_deregister(q);
>> > -
>> > -	xe_guc_ct_send(&guc->ct, action, ARRAY_SIZE(action),
>> > -		       G2H_LEN_DW_DEREGISTER_CONTEXT, 1);
>> > -}
>> > -
>> > static enum drm_gpu_sched_stat
>> > guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
>> > {
>> > @@ -1326,8 +1291,6 @@ guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
>> > 			xe_devcoredump(q, job,
>> > 				       "Schedule disable failed to respond, guc_id=%d, ret=%d, guc_read=%d",
>> > 				       q->guc->id, ret, xe_guc_read_stopped(guc));
>> > -			set_exec_queue_extra_ref(q);
>> > -			xe_exec_queue_get(q);	/* GT reset owns this */
>> > 			set_exec_queue_banned(q);
>> > 			xe_gt_reset_async(q->gt);
>> > 			xe_sched_tdr_queue_imm(sched);
>> > @@ -1380,13 +1343,7 @@ guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
>> > 		}
>> > 	}
>> >
>> > -	/* Finish cleaning up exec queue via deregister */
>> > 	set_exec_queue_banned(q);
>> > -	if (!wedged && exec_queue_registered(q) && !exec_queue_destroyed(q)) {
>> > -		set_exec_queue_extra_ref(q);
>> > -		xe_exec_queue_get(q);
>> > -		__deregister_exec_queue(guc, q);
>> > -	}
>> >
>> > 	/* Mark all outstanding jobs as bad, thus completing them */
>> > 	xe_sched_job_set_error(job, err);
>> > @@ -1928,7 +1885,7 @@ static void guc_exec_queue_stop(struct xe_guc *guc, struct xe_exec_queue *q)
>> >
>> > 	/* Clean up lost G2H + reset engine state */
>> > 	if (exec_queue_registered(q)) {
>> > -		if (exec_queue_extra_ref(q) || xe_exec_queue_is_lr(q))
>> > +		if (xe_exec_queue_is_lr(q))
>> > 			xe_exec_queue_put(q);
>> > 		else if (exec_queue_destroyed(q))
>> > 			__guc_exec_queue_destroy(guc, q);
>> > @@ -2062,11 +2019,7 @@ static void guc_exec_queue_revert_pending_state_change(struct xe_guc *guc,
>> >
>> > 	if (exec_queue_destroyed(q) && exec_queue_registered(q)) {
>> > 		clear_exec_queue_destroyed(q);
>> > -		if (exec_queue_extra_ref(q))
>> > -			xe_exec_queue_put(q);
>> > -		else
>> > -			q->guc->needs_cleanup = true;
>> > -		clear_exec_queue_extra_ref(q);
>> > +		q->guc->needs_cleanup = true;
>> > 		xe_gt_dbg(guc_to_gt(guc), "Replay CLEANUP - guc_id=%d",
>> > 			  q->guc->id);
>> > 	}
>> > @@ -2483,7 +2436,7 @@ static void handle_deregister_done(struct xe_guc *guc, struct xe_exec_queue *q)
>> >
>> > 	clear_exec_queue_registered(q);
>> >
>> > -	if (exec_queue_extra_ref(q) || xe_exec_queue_is_lr(q))
>> > +	if (xe_exec_queue_is_lr(q))
>> > 		xe_exec_queue_put(q);
>> > 	else
>> > 		__guc_exec_queue_destroy(guc, q);
>> > --
>> > 2.34.1
>> >