[Intel-gfx] [PATCH] drm/i915: Fix waiting for engines to idle

[Chris Wilson]

On Tue, May 23, 2017 at 10:19:31AM +0100, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Waiting for engines needs to happen even in the non-debug builds
> so it is incorrect to wrap it in a GEM_WARN_ON.
> 
> Call it unconditionally and add GEM_WARN so that the debug
> warning can still be emitted when things go bad.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Fixes: 25112b64b3d2 ("drm/i915: Wait for all engines to be idle as part of i915_gem_wait_for_idle()")
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: intel-gfx at lists.freedesktop.org
> Reported-by: Nick Desaulniers <nick.desaulniers at gmail.com>
> Cc: Nick Desaulniers <nick.desaulniers at gmail.com>
> ---
>  drivers/gpu/drm/i915/i915_gem.c | 3 ++-
>  drivers/gpu/drm/i915/i915_gem.h | 2 ++
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index a637cc05cc4a..ecaa21f106c8 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -3332,7 +3332,8 @@ static int wait_for_engines(struct drm_i915_private *i915)
>  	enum intel_engine_id id;
>  
>  	for_each_engine(engine, i915, id) {
> -		if (GEM_WARN_ON(wait_for_engine(engine, 50))) {
> +		if (wait_for_engine(engine, 50)) {
> +			GEM_WARN(1, "%s wait for idle timeout", engine->name);

Nice touching adding the engine->name
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

>  			i915_gem_set_wedged(i915);
>  			return -EIO;
>  		}
> diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h
> index ee54597465b6..cefc6cf96a60 100644
> --- a/drivers/gpu/drm/i915/i915_gem.h
> +++ b/drivers/gpu/drm/i915/i915_gem.h
> @@ -30,6 +30,7 @@
>  #ifdef CONFIG_DRM_I915_DEBUG_GEM
>  #define GEM_BUG_ON(expr) BUG_ON(expr)
>  #define GEM_WARN_ON(expr) WARN_ON(expr)
> +#define GEM_WARN(condition, format, ...) WARN(condition, format, __VA_ARGS__)
>  
>  #define GEM_DEBUG_DECL(var) var
>  #define GEM_DEBUG_EXEC(expr) expr
> @@ -38,6 +39,7 @@
>  #else
>  #define GEM_BUG_ON(expr) BUILD_BUG_ON_INVALID(expr)
>  #define GEM_WARN_ON(expr) (BUILD_BUG_ON_INVALID(expr), 0)
> +#define GEM_WARN(condition, format, ...) BUILD_BUG_ON_INVALID(condition)

WARNs can be used as part of an if(), so perhaps

#define GEM_WARN(condition, format, ...) (BUILD_BUG_ON_INVALID(condition), 0)
#define GEM_WARN_ON(expr) GEM_WARN((expr), 0)

?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre