Re: [PATCH 1/4] drm: Really never disable vblank irqs for offdelay==0

[Matt Roper <matthew.d.roper@intel.com>]

On Wed, Sep 10, 2014 at 05:36:08PM +0200, Daniel Vetter wrote:
> With the new support for immediate vblank disabling we always disabled
> the vblank interrupt right away, irrespective of the vblank offdelay
> setting.
> 
> But being able to let vblanks run forever is fairly useful for
> debugging, so restore that behaviour.
> 
> Suggested-by: Mario Kleiner <mario.kleiner.de@gmail.com>
> Cc: Mario Kleiner <mario.kleiner.de@gmail.com>
> Cc: Matt Roper <matthew.d.roper@intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>

> ---
>  drivers/gpu/drm/drm_irq.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
> index a75da075927c..6eb015020af2 100644
> --- a/drivers/gpu/drm/drm_irq.c
> +++ b/drivers/gpu/drm/drm_irq.c
> @@ -1024,9 +1024,11 @@ void drm_vblank_put(struct drm_device *dev, int crtc)
>  
>  	/* Last user schedules interrupt disable */
>  	if (atomic_dec_and_test(&vblank->refcount)) {
> -		if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
> +		if (drm_vblank_offdelay == 0)
> +			return;
> +		else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
>  			vblank_disable_fn((unsigned long)vblank);
> -		else if (drm_vblank_offdelay > 0)
> +		else
>  			mod_timer(&vblank->disable_timer,
>  				  jiffies + ((drm_vblank_offdelay * HZ)/1000));
>  	}
> -- 
> 1.9.3
> 

-- 
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795