Re: [PATCH] drm/i915: Don't reinit hpd interrupts after gpu reset

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Mon, Sep 08, 2014 at 06:17:18PM +0200, Daniel Vetter wrote:
> Somehow I've overlooked this when simplifying the irq reinit
> scheme on gen4.5+ in
> 
> commit 78ad455fd229c6f6cc2f390ccbe0d8f1a62d55a9
> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> Date:   Thu May 22 22:18:21 2014 +0200
> 
>     drm/i915: Improve irq handling after gpu resets
> 
> Since display interrups in general survive a gpu reset on those
> platforms there's also no need to reinit the hotplug settings.
> 
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

This matches my observations on actual hardware. IIRC I looked at the
reset vs. interrupt registers at least on ILK and IVB and the registers
retained their current values on both.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> ---
>  drivers/gpu/drm/i915/i915_drv.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 8ff375538b5d..70cc38924040 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -871,8 +871,6 @@ int i915_reset(struct drm_device *dev)
>  		 */
>  		if (INTEL_INFO(dev)->gen > 5)
>  			intel_reset_gt_powersave(dev);
> -
> -		intel_hpd_init(dev);
>  	} else {
>  		mutex_unlock(&dev->struct_mutex);
>  	}
> -- 
> 2.0.1

-- 
Ville Syrjälä
Intel OTC