[PATCH 14/21] drm/dp: Use drm_dp_aux_rd_interval()

Philipp Zabel p.zabel at pengutronix.de
Thu Aug 8 13:17:33 UTC 2019


On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> From: Thierry Reding <treding at nvidia.com>
> 
> Make use of the newly added drm_dp_aux_rd_interval() helper in existing
> DP link training helpers and add comments about minimum required delays
> mandated by the DP specification.

This patch does not add any comments:

> 
> Signed-off-by: Thierry Reding <treding at nvidia.com>
> ---
>  drivers/gpu/drm/drm_dp_helper.c | 26 +++-----------------------
>  1 file changed, 3 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 344f887fef2c..1fb3c27cd012 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -122,17 +122,7 @@ EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
>  
>  void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
>  {
> -	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> -					DP_TRAINING_AUX_RD_MASK;
> -
> -	if (rd_interval > 4)
> -		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
> -			      rd_interval);
> -
> -	if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
> -		rd_interval = 100;
> -	else
> -		rd_interval *= 4;
> +	unsigned int rd_interval = drm_dp_aux_rd_interval(dpcd);
>  
>  	usleep_range(rd_interval, rd_interval * 2);
>  }
> @@ -140,19 +130,9 @@ EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
>  
>  void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
>  {
> -	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> -					DP_TRAINING_AUX_RD_MASK;
> -
> -	if (rd_interval > 4)
> -		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
> -			      rd_interval);
> +	unsigned int min = drm_dp_aux_rd_interval(dpcd);
>  
> -	if (rd_interval == 0)
> -		rd_interval = 400;
> -	else
> -		rd_interval *= 4;
> -
> -	usleep_range(rd_interval, rd_interval * 2);
> +	usleep_range(min, min * 2);
>  }
>  EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
>  

regards
Philipp


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