[PATCH 1/2] drm/i915: Replace nondescript 'WARN_ON(!lret)' with a sensible error message

[Maarten Lankhorst]

Op 18-04-16 om 13:29 schreef ville.syrjala at linux.intel.com:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> When a vblank wait times out in intel_atomic_wait_for_vblanks() we just
> get a cryptic 'WARN_ON(!ret)' backtrace in dmesg. Repace it with
> something that tells you what actually happened.
>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 4cca155376be..7bdbe4b03591 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -13523,7 +13523,7 @@ static void intel_atomic_wait_for_vblanks(struct drm_device *dev,
>  					drm_crtc_vblank_count(crtc),
>  				msecs_to_jiffies(50));
>  
> -		WARN_ON(!lret);
> +		WARN(!lret, "pipe %c vblank wait timed out\n", pipe_name(pipe));
>  
>  		drm_crtc_vblank_put(crtc);
>  	}
This helper function was never meant to last as long as it did. :(

Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>