[PATCH 1/1] drm: fix drm_update_vblank_count for software vblank counter

[Ville Syrjälä]

On Wed, Sep 30, 2015 at 02:29:49PM +0200, Vincent Abriou wrote:
> Drivers with software vblank counter relies on the on drm core to update
> vblank counter and they should not be concern about the warning that
> check hardware counter coherency.
> 
> Further, the generic message that tracks the current and last counter
> values must be counter type (hardware or software) agnostic.
> 
> Cc: Ville Syrj?l? <ville.syrjala at linux.intel.com>
> Signed-off-by: Vincent Abriou <vincent.abriou at st.com>

I sent a patch to get rid of the drm_vblank_count() abuse in all
drivers. That will get rid of the WARN too.

> ---
>  drivers/gpu/drm/drm_irq.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
> index 88fbee4..88041b4 100644
> --- a/drivers/gpu/drm/drm_irq.c
> +++ b/drivers/gpu/drm/drm_irq.c
> @@ -219,11 +219,12 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
>  	} else {
>  		/* some kind of default for drivers w/o accurate vbl timestamping */
>  		diff = (flags & DRM_CALLED_FROM_VBLIRQ) != 0;
> +		if (diff == 0)
> +			return;
>  	}
>  
> -	DRM_DEBUG("updating vblank count on crtc %u:"
> -		  " current=%u, diff=%u, hw=%u hw_last=%u\n",
> -		  pipe, vblank->count, diff, cur_vblank, vblank->last);
> +	DRM_DEBUG("updating vblank count on crtc %u: diff=%u cur=%u last=%u\n",
> +		  pipe, diff, cur_vblank, vblank->last);
>  
>  	if (diff == 0) {
>  		WARN_ON_ONCE(cur_vblank != vblank->last);
> -- 
> 1.9.1

-- 
Ville Syrjälä
Intel OTC