[Intel-gfx] [PATCH] drm/i915: Use dpcd read wake for sink crc calls.

[Zanoni, Paulo R]

Em Qui, 2015-08-20 às 16:23 -0700, Rodrigo Vivi escreveu:
> Let's use a native read with retry as suggested per spec to
> fix Sink CRC on SKL when PSR is enabled.
> 
> With PSR enabled panel is probably taking more time to wake
> and dpcd read is faling.

Does this commit actually fix any known problem with Sink CRC? Or is it
just a try? It would be nice to have this clarified in the commit
message.

Anyway, it looks correct, so:
Reviewed-by: Paulo Zanoni <paulo.r.zanoni at intel.com>

> 
> v2: Fix my email domain on commit message. Thanks Rafael.
> 
> Cc: Rafael Antognolli <rafael.antognolli at intel.com>
> Cc: Sonika Jindal <sonika.jindal at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c 
> b/drivers/gpu/drm/i915/intel_dp.c
> index d32ce48..34f5e33 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -4037,7 +4037,8 @@ static int intel_dp_sink_crc_stop(struct 
> intel_dp *intel_dp)
>  	u8 buf;
>  	int ret = 0;
>  
> -	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf) < 
> 0) {
> +	if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_TEST_SINK,
> +				    &buf, 1) < 0) {
>  		DRM_DEBUG_KMS("Sink CRC couldn't be stopped 
> properly\n");
>  		ret = -EIO;
>  		goto out;
> @@ -4069,7 +4070,8 @@ static int intel_dp_sink_crc_start(struct 
> intel_dp *intel_dp)
>  			return ret;
>  	}
>  
> -	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, 
> &buf) < 0)
> +	if (intel_dp_dpcd_read_wake(&intel_dp->aux, 
> DP_TEST_SINK_MISC,
> +				    &buf, 1) < 0)
>  		return -EIO;
>  
>  	if (!(buf & DP_TEST_CRC_SUPPORTED))
> @@ -4077,7 +4079,7 @@ static int intel_dp_sink_crc_start(struct 
> intel_dp *intel_dp)
>  
>  	intel_dp->sink_crc.last_count = buf & DP_TEST_COUNT_MASK;
>  
> -	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf) < 
> 0)
> +	if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_TEST_SINK, 
> &buf, 1) < 0)
>  		return -EIO;
>  
>  	hsw_disable_ips(intel_crtc);
> @@ -4109,8 +4111,8 @@ int intel_dp_sink_crc(struct intel_dp 
> *intel_dp, u8 *crc)
>  	do {
>  		intel_wait_for_vblank(dev, intel_crtc->pipe);
>  
> -		if (drm_dp_dpcd_readb(&intel_dp->aux,
> -				      DP_TEST_SINK_MISC, &buf) < 0) 
> {
> +		if (intel_dp_dpcd_read_wake(&intel_dp->aux,
> +					    DP_TEST_SINK_MISC, &buf, 
> 1) < 0) {
>  			ret = -EIO;
>  			goto stop;
>  		}
> @@ -4123,7 +4125,8 @@ int intel_dp_sink_crc(struct intel_dp 
> *intel_dp, u8 *crc)
>  		if (count == 0)
>  			intel_dp->sink_crc.last_count = 0;
>  
> -		if (drm_dp_dpcd_read(&intel_dp->aux, 
> DP_TEST_CRC_R_CR, crc, 6) < 0) {
> +		if (intel_dp_dpcd_read_wake(&intel_dp->aux, 
> DP_TEST_CRC_R_CR,
> +					    crc, 6) < 0) {
>  			ret = -EIO;
>  			goto stop;
>  		}