[Intel-gfx] [PATCH 01/10] drm/i915: Remove "VLV magic" from irq setup

[Imre Deak]

On ma, 2016-04-11 at 16:56 +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> No clue what this is supposed to achieve. I think it's been there
> since
> the very beginning, so presumably some kind of kludge for very early
> silicon. Let's just throw it out.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_irq.c | 6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_irq.c
> b/drivers/gpu/drm/i915/i915_irq.c
> index 679f08c944ef..1d21ebfffd4d 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3319,12 +3319,6 @@ static void valleyview_irq_preinstall(struct
> drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> -	/* VLV magic */
> -	I915_WRITE(VLV_IMR, 0);
> -	I915_WRITE(RING_IMR(RENDER_RING_BASE), 0);
> -	I915_WRITE(RING_IMR(GEN6_BSD_RING_BASE), 0);
> -	I915_WRITE(RING_IMR(BLT_RING_BASE), 0);
> -

AFAICS this would also leave the ring interrupts unmasked before we
called ring->get_irq(), so at least the change is a fix for that. I
haven't found any explanation for the above either, so I guess the best
we can do at this point is to see if things continue to work without
it:

Reviewed-by: Imre Deak <imre.deak at intel.com>

>  	gen5_gt_irq_reset(dev);
>  
>  	I915_WRITE(DPINVGTT, DPINVGTT_STATUS_MASK);