Re: [PATCH] drm/display: Include missing DPCD definitions from DP2.0 spec

[Harry Wentland <harry.wentland@amd.com>]

The commit subject is very generic. A better one might be
"Add missing Adaptive Sync DPCD definitions"

On 12/8/22 14:25, Sung Joon Kim wrote:
> The missing DPCD defintions from DP2.0 spec is as follows:
> 
> DOWNSPREAD_CTRL (107h):
> 	ADAPTIVE_SYNC_SDP_EN (bit 6)
> 		For sink devices that support Adaptive-Sync operation
> 		and Panel Replay
> 
> DPRX_FEATURE_ENUMERATION_LIST_CONT_1 (2214h):
> 	ADAPTIVE_SYNC_SDP_SUPPORTED (bit 0)
> 		Bit to check sink device has Adaptive-Sync capability
> 	AS_SDP_FIRST_HALF_LINE_OR_3840_PIXEL_CYCLE_WINDOW_NOT_SUPPORTED (bit 1)
> 		A sink device that clears this bit will generate VSync pulse
> 		leading edge of the HDMI output on the line count at which
> 		Adaptive-Sync SDP is received as long as source device transmits
> 		Adaptive-Sync SDP either in first line or first 3840 pixel cycles
> 		of the line whichever occurs first.
> 	VSC_EXT_SDP_FRAMEWORK_VERSION_1_SUPPORTED (bit 4)
> 		Bit to check sink device has SDP framework version 1 capability
> ---
>  include/drm/display/drm_dp.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/include/drm/display/drm_dp.h b/include/drm/display/drm_dp.h
> index 4d0abe4c7ea9..4f33b6aeb91e 100644
> --- a/include/drm/display/drm_dp.h
> +++ b/include/drm/display/drm_dp.h
> @@ -603,6 +603,7 @@
>  
>  #define DP_DOWNSPREAD_CTRL		    0x107
>  # define DP_SPREAD_AMP_0_5		    (1 << 4)
> +# define DP_ADAPTIVE_SYNC_SDP_EN            (1 << 6)

We tend to stick with the naming from the spec to allow
people to find things more easily. Please change this to:
DP_FIXED_VTOTAL_AS_SDP_EN_IN_PR_ACTIVE

Harry

>  # define DP_MSA_TIMING_PAR_IGNORE_EN	    (1 << 7) /* eDP */
>  
>  #define DP_MAIN_LINK_CHANNEL_CODING_SET	    0x108
> @@ -1105,6 +1106,11 @@
>  # define DP_VSC_EXT_CEA_SDP_SUPPORTED			(1 << 6)  /* DP 1.4 */
>  # define DP_VSC_EXT_CEA_SDP_CHAINING_SUPPORTED		(1 << 7)  /* DP 1.4 */
>  
> +#define DP_DPRX_FEATURE_ENUMERATION_LIST_CONT_1         0x2214 /* 2.0 E11 */
> +# define DP_ADAPTIVE_SYNC_SDP_SUPPORTED    (1 << 0)
> +# define DP_AS_SDP_FIRST_HALF_LINE_OR_3840_PIXEL_CYCLE_WINDOW_NOT_SUPPORTED (1 << 1)
> +# define DP_VSC_EXT_SDP_FRAMEWORK_VERSION_1_SUPPORTED  (1 << 4)
> +
>  #define DP_128B132B_SUPPORTED_LINK_RATES       0x2215 /* 2.0 */
>  # define DP_UHBR10                             (1 << 0)
>  # define DP_UHBR20                             (1 << 1)