Re: [RESEND PATCH 6/7] drm/dp: Add a helper to get the SDP type as a string

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Apr 24, 2026 at 03:04:23PM +0530, Ankit Nautiyal wrote:
> Introduce dp_sdp_type_get_name() to get the SDP type as a string.
> Use this to log the SDP type based on the sdp_type fields of the
> VSC and AS SDPs instead of the hardcoded strings.
> 
> While at it, rename "SDP : AS_SDP" to "SDP : Adaptive Sync"
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/display/drm_dp_helper.c | 36 ++++++++++++++++++++++---
>  1 file changed, 32 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
> index e29958f8b0b6..102328d9022d 100644
> --- a/drivers/gpu/drm/display/drm_dp_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_helper.c
> @@ -3487,10 +3487,38 @@ static const char *dp_content_type_get_name(enum dp_content_type content_type)
>  	}
>  }
>  
> +static const char *dp_sdp_type_get_name(unsigned char type)

I dislike this "_get_" stuff in the name. It's redundant, and can be
confused with some refcounting related get/put. I really wish people
would stop using it...

But looks like all the other similar things here already use the "_get_"
naming, so I guess we should stick to a consistent style for now.

> +{
> +	switch (type) {
> +	case DP_SDP_AUDIO_TIMESTAMP:
> +		return "Audio Timestamp";

"Audio_TimeStamp" to match the spec.

> +	case DP_SDP_AUDIO_STREAM:
> +		return "Audio Stream";

"Audio_Stream"

> +	case DP_SDP_EXTENSION:
> +		return "Extension";
> +	case DP_SDP_AUDIO_COPYMANAGEMENT:
> +		return "Audio Copy Management";

"Audio_CopyManagement"

> +	case DP_SDP_ISRC:
> +		return "ISRC";
> +	case DP_SDP_VSC:
> +		return "VSC";
> +	case DP_SDP_PPS:
> +		return "PPS";
> +	case DP_SDP_VSC_EXT_VESA:
> +		return "VSC EXT VESA";
> +	case DP_SDP_VSC_EXT_CEA:
> +		return "VSC EXT CEA";

Looks like the spec does favor the acronym form for all of
those. So I guess that's what we want here as well. The ' '
should all be '_' to match the spec though.

> +	case DP_SDP_ADAPTIVE_SYNC:
> +		return "Adaptive Sync";

"Adaptive-Sync" seems to be the preferred form for this
in the spec.

> +	default:
> +		return "Unknown";
> +	}
> +}
> +
>  void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc)
>  {
> -	drm_printf(p, "DP SDP: VSC, revision %u, length %u\n",
> -		   vsc->revision, vsc->length);
> +	drm_printf(p, "DP SDP: %s, revision %u, length %u\n",
> +		   dp_sdp_type_get_name(vsc->sdp_type), vsc->revision, vsc->length);
>  	drm_printf(p, "    pixelformat: %s\n",
>  		   dp_pixelformat_get_name(vsc->pixelformat));
>  	drm_printf(p, "    colorimetry: %s\n",
> @@ -3505,8 +3533,8 @@ EXPORT_SYMBOL(drm_dp_vsc_sdp_log);
>  
>  void drm_dp_as_sdp_log(struct drm_printer *p, const struct drm_dp_as_sdp *as_sdp)
>  {
> -	drm_printf(p, "DP SDP: AS_SDP, revision %u, length %u\n",
> -		   as_sdp->revision, as_sdp->length);
> +	drm_printf(p, "DP SDP: %s, revision %u, length %u\n",
> +		   dp_sdp_type_get_name(as_sdp->sdp_type), as_sdp->revision, as_sdp->length);
>  	drm_printf(p, "    vtotal: %d\n", as_sdp->vtotal);
>  	drm_printf(p, "    target_rr: %d\n", as_sdp->target_rr);
>  	drm_printf(p, "    duration_incr_ms: %d\n", as_sdp->duration_incr_ms);
> -- 
> 2.45.2

-- 
Ville Syrjälä
Intel