[1/5] drm/i915/execlists: Set priority hint prior to submission
diff mbox series

Message ID 20190821155728.2839-1-chris@chris-wilson.co.uk
State New
Headers show
Series
  • [1/5] drm/i915/execlists: Set priority hint prior to submission
Related show

Commit Message

Chris Wilson Aug. 21, 2019, 3:57 p.m. UTC
Since we now run process_csb() outside of the engine->active.lock, we
can process a CS-event immediately upon our ELSP write. As we currently
inspect the pending queue *after* the ELSP write, there is an
opportunity for a CS-event to update the pending queue before we can
read it, making ourselves chases an invalid pointer.

Fixes: df403069029d ("drm/i915/execlists: Lift process_csb() out of the irq-off spinlock")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_lrc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Mika Kuoppala Aug. 21, 2019, 4:18 p.m. UTC | #1
Chris Wilson <chris@chris-wilson.co.uk> writes:

> Since we now run process_csb() outside of the engine->active.lock, we
> can process a CS-event immediately upon our ELSP write. As we currently
> inspect the pending queue *after* the ELSP write, there is an
> opportunity for a CS-event to update the pending queue before we can
> read it, making ourselves chases an invalid pointer.
>
> Fixes: df403069029d ("drm/i915/execlists: Lift process_csb() out of the irq-off spinlock")
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>

Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>

> ---
>  drivers/gpu/drm/i915/gt/intel_lrc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index 44780e7fafec..d42584439f51 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -1335,9 +1335,9 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
>  	if (submit) {
>  		*port = execlists_schedule_in(last, port - execlists->pending);
>  		memset(port + 1, 0, (last_port - port) * sizeof(*port));
> -		execlists_submit_ports(engine);
>  		execlists->switch_priority_hint =
>  			switch_prio(engine, *execlists->pending);
> +		execlists_submit_ports(engine);
>  	} else {
>  		ring_set_paused(engine, 0);
>  	}
> -- 
> 2.23.0.rc1

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 44780e7fafec..d42584439f51 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1335,9 +1335,9 @@  static void execlists_dequeue(struct intel_engine_cs *engine)
 	if (submit) {
 		*port = execlists_schedule_in(last, port - execlists->pending);
 		memset(port + 1, 0, (last_port - port) * sizeof(*port));
-		execlists_submit_ports(engine);
 		execlists->switch_priority_hint =
 			switch_prio(engine, *execlists->pending);
+		execlists_submit_ports(engine);
 	} else {
 		ring_set_paused(engine, 0);
 	}