[Intel-gfx] [PATCH 04/12] drm/i915/gt: Treat a busy timeline as 'active' while waiting

[Tvrtko Ursulin]

On 06/10/2019 17:49, Chris Wilson wrote:
> If we cannot claim the timeline->mutex while preparing for a wait on it,
> we have to skip the timeline. In doing so, treat it as active so that
> under a intel_gt_wait_for_idle() loop, we repeat the wait after
> scheduling away.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/gt/intel_gt_requests.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_requests.c b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
> index d69e78478eea..ca606b79fd5e 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_requests.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
> @@ -34,8 +34,10 @@ long intel_gt_retire_requests_timeout(struct intel_gt *gt, long timeout)
>   
>   	spin_lock_irqsave(&timelines->lock, flags);
>   	list_for_each_entry_safe(tl, tn, &timelines->active_list, link) {
> -		if (!mutex_trylock(&tl->mutex))
> +		if (!mutex_trylock(&tl->mutex)) {
> +			active_count++; /* report busy to caller, try again? */
>   			continue;
> +		}
>   
>   		intel_timeline_get(tl);
>   		GEM_BUG_ON(!tl->active_count);
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko