* [PATCH] drm/i915: Return early for await_start on same timeline
@ 2020-03-05 13:48 Chris Wilson
2020-03-05 14:50 ` Tvrtko Ursulin
0 siblings, 1 reply; 2+ messages in thread
From: Chris Wilson @ 2020-03-05 13:48 UTC (permalink / raw)
To: intel-gfx; +Cc: Chris Wilson, Tvrtko Ursulin, stable
Requests within a timeline are ordered by that timeline, so awaiting for
the start of a request within the timeline is a no-op. This used to work
by falling out of the mutex_trylock() as the signaler and waiter had the
same timeline and not returning an error.
Fixes: 6a79d848403d ("drm/i915: Lock signaler timeline while navigating")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.5+
---
drivers/gpu/drm/i915/i915_request.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 46dae33c1a20..ca5361eb1f0b 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -837,8 +837,8 @@ i915_request_await_start(struct i915_request *rq, struct i915_request *signal)
struct dma_fence *fence;
int err;
- GEM_BUG_ON(i915_request_timeline(rq) ==
- rcu_access_pointer(signal->timeline));
+ if (i915_request_timeline(rq) == rcu_access_pointer(signal->timeline))
+ return 0;
if (i915_request_started(signal))
return 0;
--
2.25.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] drm/i915: Return early for await_start on same timeline
2020-03-05 13:48 [PATCH] drm/i915: Return early for await_start on same timeline Chris Wilson
@ 2020-03-05 14:50 ` Tvrtko Ursulin
0 siblings, 0 replies; 2+ messages in thread
From: Tvrtko Ursulin @ 2020-03-05 14:50 UTC (permalink / raw)
To: Chris Wilson, intel-gfx; +Cc: stable
On 05/03/2020 13:48, Chris Wilson wrote:
> Requests within a timeline are ordered by that timeline, so awaiting for
> the start of a request within the timeline is a no-op. This used to work
> by falling out of the mutex_trylock() as the signaler and waiter had the
> same timeline and not returning an error.
>
> Fixes: 6a79d848403d ("drm/i915: Lock signaler timeline while navigating")
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
> Cc: <stable@vger.kernel.org> # v5.5+
> ---
> drivers/gpu/drm/i915/i915_request.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
> index 46dae33c1a20..ca5361eb1f0b 100644
> --- a/drivers/gpu/drm/i915/i915_request.c
> +++ b/drivers/gpu/drm/i915/i915_request.c
> @@ -837,8 +837,8 @@ i915_request_await_start(struct i915_request *rq, struct i915_request *signal)
> struct dma_fence *fence;
> int err;
>
> - GEM_BUG_ON(i915_request_timeline(rq) ==
> - rcu_access_pointer(signal->timeline));
> + if (i915_request_timeline(rq) == rcu_access_pointer(signal->timeline))
> + return 0;
>
> if (i915_request_started(signal))
> return 0;
>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Regards,
Tvrtko
^ permalink raw reply [flat|nested] 2+ messages in thread
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2020-03-05 14:50 ` Tvrtko Ursulin
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