Re: [PATCH] drm/display/dp: Rename bit 4 of DPCD TEST_REQUEST to match DP2.1 spec

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 10/28/25 11:28 PM, Khaled Almahallawy wrote:
> The DP_TEST_LINK_FAUX_PATTERN field was deprecated in the DP 1.3 spec.
> Update its name to align with the DP 2.1 definition and reflect its
> actual use in the code. No functional changes.
> 
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: Rob Clark <robin.clark@oss.qualcomm.com>
> Cc: Dmitry Baryshkov <lumag@kernel.org>
> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
> Cc: Sean Paul <sean@poorly.run>
> Signed-off-by: Khaled Almahallawy <khaled.almahallawy@intel.com>
> ---
>  drivers/gpu/drm/msm/dp/dp_link.c | 2 +-
>  include/drm/display/drm_dp.h     | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
> index 66e1bbd80db3..5d465cf4dbc2 100644
> --- a/drivers/gpu/drm/msm/dp/dp_link.c
> +++ b/drivers/gpu/drm/msm/dp/dp_link.c
> @@ -665,7 +665,7 @@ static int msm_dp_link_parse_request(struct msm_dp_link_private *link)
>  		return rlen;
>  	}
>  
> -	if (!data || (data == DP_TEST_LINK_FAUX_PATTERN)) {
> +	if (!data || (data == DP_TEST_PHY_TEST_CHANNEL_CODING_TYPE)) {
>  		drm_dbg_dp(link->drm_dev, "link 0x%x not supported\n", data);
>  		goto end;
>  	}
> diff --git a/include/drm/display/drm_dp.h b/include/drm/display/drm_dp.h
> index e4eebabab975..610b8cbf1125 100644
> --- a/include/drm/display/drm_dp.h
> +++ b/include/drm/display/drm_dp.h
> @@ -849,7 +849,7 @@
>  # define DP_TEST_LINK_VIDEO_PATTERN	    (1 << 1)
>  # define DP_TEST_LINK_EDID_READ		    (1 << 2)
>  # define DP_TEST_LINK_PHY_TEST_PATTERN	    (1 << 3) /* DPCD >= 1.1 */
> -# define DP_TEST_LINK_FAUX_PATTERN	    (1 << 4) /* DPCD >= 1.2 */
> +# define DP_TEST_PHY_TEST_CHANNEL_CODING_TYPE	    (1 << 4)

I think it'd be useful to keep a comment of what it was before the
deprecation and rename

Konrad