[Intel-gfx] [PATCH] drm/i915: Ignore GTFIFODBG FIFO free entry fields on CHV

[Daniel Vetter]

On Wed, Apr 13, 2016 at 09:09:30PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> On CHV GTFIFODBG has some read-only bits to indicate the number
> of free FIFO entries. Ignore these when checking to see if any
> of the sticky error bits are set.
> 
> This gets rid of these during device resume:
> [drm:cherryview_enable_rps] GT fifo had a previous error 1080000
> 
> While at it, move the assignments out of the if().
> 
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Not entirely sure we don't want to filter even more, but these we want to
filter for sure.

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Also just realized that we don't check this on in the chv_write functions.
Should we?
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_reg.h | 2 ++
>  drivers/gpu/drm/i915/intel_pm.c | 9 ++++++---
>  2 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index cea5a390d8c9..a0eaefc77602 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -6866,6 +6866,8 @@ enum skl_disp_power_wells {
>  #define  VLV_SPAREG2H				_MMIO(0xA194)
>  
>  #define  GTFIFODBG				_MMIO(0x120000)
> +#define    GT_FIFO_SBDEDICATE_FREE_ENTRY_CHV	(0x1f << 20)
> +#define    GT_FIFO_FREE_ENTRIES_CHV		(0x7f << 13)
>  #define    GT_FIFO_SBDROPERR			(1<<6)
>  #define    GT_FIFO_BLOBDROPERR			(1<<5)
>  #define    GT_FIFO_SB_READ_ABORTERR		(1<<4)
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index b8e395ad05ac..b7c218602c6e 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4997,7 +4997,8 @@ static void gen6_enable_rps(struct drm_device *dev)
>  	I915_WRITE(GEN6_RC_STATE, 0);
>  
>  	/* Clear the DBG now so we don't confuse earlier errors */
> -	if ((gtfifodbg = I915_READ(GTFIFODBG))) {
> +	gtfifodbg = I915_READ(GTFIFODBG);
> +	if (gtfifodbg) {
>  		DRM_ERROR("GT fifo had a previous error %x\n", gtfifodbg);
>  		I915_WRITE(GTFIFODBG, gtfifodbg);
>  	}
> @@ -5528,7 +5529,8 @@ static void cherryview_enable_rps(struct drm_device *dev)
>  
>  	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
>  
> -	gtfifodbg = I915_READ(GTFIFODBG);
> +	gtfifodbg = I915_READ(GTFIFODBG) & ~(GT_FIFO_SBDEDICATE_FREE_ENTRY_CHV |
> +					     GT_FIFO_FREE_ENTRIES_CHV);
>  	if (gtfifodbg) {
>  		DRM_DEBUG_DRIVER("GT fifo had a previous error %x\n",
>  				 gtfifodbg);
> @@ -5627,7 +5629,8 @@ static void valleyview_enable_rps(struct drm_device *dev)
>  
>  	valleyview_check_pctx(dev_priv);
>  
> -	if ((gtfifodbg = I915_READ(GTFIFODBG))) {
> +	gtfifodbg = I915_READ(GTFIFODBG);
> +	if (gtfifodbg) {
>  		DRM_DEBUG_DRIVER("GT fifo had a previous error %x\n",
>  				 gtfifodbg);
>  		I915_WRITE(GTFIFODBG, gtfifodbg);
> -- 
> 2.7.4
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch