diff mbox series

[v9,27/70] drm/i915: Make __engine_unpark() compatible with ww locking.

Message ID 20210323155059.628690-28-maarten.lankhorst@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series drm/i915: Remove obj->mm.lock! | expand

Commit Message

Maarten Lankhorst March 23, 2021, 3:50 p.m. UTC 
Take the ww lock around engine_unpark. Because of the
many many places where rpm is used, I chose the safest option
and used a trylock to opportunistically take this lock for
__engine_unpark.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_engine_pm.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Daniel Vetter March 24, 2021, 12:37 p.m. UTC | #1 
On Tue, Mar 23, 2021 at 04:50:16PM +0100, Maarten Lankhorst wrote:
> Take the ww lock around engine_unpark. Because of the
> many many places where rpm is used, I chose the safest option
> and used a trylock to opportunistically take this lock for
> __engine_unpark.

Correct choice, runtime pm resume is on the critical path for dma-fence
(we might need to wake up the device for e.g. atomic modeset commits), so
definitely can't have a dma_resv_lock in here.
-Daniel

> 
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_engine_pm.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> index 27d9d17b35cb..bddc5c98fb04 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> @@ -27,12 +27,16 @@ static void dbg_poison_ce(struct intel_context *ce)
>  		int type = i915_coherent_map_type(ce->engine->i915);
>  		void *map;
>  
> +		if (!i915_gem_object_trylock(obj))
> +			return;
> +
>  		map = i915_gem_object_pin_map(obj, type);
>  		if (!IS_ERR(map)) {
>  			memset(map, CONTEXT_REDZONE, obj->base.size);
>  			i915_gem_object_flush_map(obj);
>  			i915_gem_object_unpin_map(obj);
>  		}
> +		i915_gem_object_unlock(obj);
>  	}
>  }
>  
> -- 
> 2.31.0
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
index 27d9d17b35cb..bddc5c98fb04 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
@@ -27,12 +27,16 @@  static void dbg_poison_ce(struct intel_context *ce)
 		int type = i915_coherent_map_type(ce->engine->i915);
 		void *map;
 
+		if (!i915_gem_object_trylock(obj))
+			return;
+
 		map = i915_gem_object_pin_map(obj, type);
 		if (!IS_ERR(map)) {
 			memset(map, CONTEXT_REDZONE, obj->base.size);
 			i915_gem_object_flush_map(obj);
 			i915_gem_object_unpin_map(obj);
 		}
+		i915_gem_object_unlock(obj);
 	}
 }