Re: [PATCH 2/6] drm/i915: Fix ILK reset wait

[Daniel Vetter <daniel@ffwll.ch>]

On Mon, May 19, 2014 at 09:30:25AM -0700, Jesse Barnes wrote:
> On Mon, 19 May 2014 19:23:23 +0300
> ville.syrjala@linux.intel.com wrote:
> 
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > We should be waiting for the reset bit to clear, not remain set.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_uncore.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> > index 0e333f2..d79db88 100644
> > --- a/drivers/gpu/drm/i915/intel_uncore.c
> > +++ b/drivers/gpu/drm/i915/intel_uncore.c
> > @@ -1000,7 +1000,8 @@ static int ironlake_do_reset(struct drm_device *dev)
> >  	gdrst &= ~GRDOM_MASK;
> >  	I915_WRITE(MCHBAR_MIRROR_BASE + ILK_GDSR,
> >  		   gdrst | GRDOM_RENDER | GRDOM_RESET_ENABLE);
> > -	ret = wait_for(I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) & 0x1, 500);
> > +	ret = wait_for((I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) &
> > +			GRDOM_RESET_ENABLE) == 0, 500);
> >  	if (ret)
> >  		return ret;
> >  
> > @@ -1008,7 +1009,8 @@ static int ironlake_do_reset(struct drm_device *dev)
> >  	gdrst &= ~GRDOM_MASK;
> >  	I915_WRITE(MCHBAR_MIRROR_BASE + ILK_GDSR,
> >  		   gdrst | GRDOM_MEDIA | GRDOM_RESET_ENABLE);
> > -	return wait_for(I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) & 0x1, 500);
> > +	return wait_for((I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) &
> > +			 GRDOM_RESET_ENABLE) == 0, 500);
> >  }
> >  
> >  static int gen6_do_reset(struct drm_device *dev)
> 
> Arg, I lost the docs on this, but it matches what I remember.
> 
> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Was this tested on an ilk? I remember writing a similar patch and I didn't
apply it due to conflict with reality.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch