[Intel-gfx] [PATCH] drm/i915/fbc: only update no_fbc_reason when active

[Daniel Vetter]

On Fri, Aug 11, 2017 at 09:23:27AM +0200, Daniel Vetter wrote:
> In our snb farm in CI we have plenty of underruns, but not enough
> stolen memory to enable fbc. Which means every time there's an
> underrun the no_fbc_reason swichtes to something that makes
> kms_frontbuffer_tracking fail instead of skip, adding massive amounts
> of additional noise to igt test runs.
> 
> Make sure we don't try to disable fbc when it's off already.
> 
> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>

Note this seems to be the real bug that's causing all the spurious noise
on snb CI in the full run. So pretty important to land this fast.
-Daniel

> ---
>  drivers/gpu/drm/i915/intel_fbc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
> index 860b8c26d29b..4015b1e716e5 100644
> --- a/drivers/gpu/drm/i915/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/intel_fbc.c
> @@ -1216,7 +1216,7 @@ static void intel_fbc_underrun_work_fn(struct work_struct *work)
>  	mutex_lock(&fbc->lock);
>  
>  	/* Maybe we were scheduled twice. */
> -	if (fbc->underrun_detected)
> +	if (fbc->underrun_detected || !fbc->enabled)
>  		goto out;
>  
>  	DRM_DEBUG_KMS("Disabling FBC due to FIFO underrun.\n");
> -- 
> 2.13.3
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch