Re: [PATCH] drm/msm/dp: Enable support for eDP v1.4+ link rates table

[Dmitry Baryshkov]

On 16/12/2025 16:31, Dale Whinham wrote:
> On 15/12/2025 22:15, Dmitry Baryshkov wrote:
> > I'd suggest following i915 and writing DP_LANE_COUNT_SET before
> > DP_LINK_BW_SET.
>
> Thank you - made this change for v2.
>
> > > +    /* For eDP v1.4+, parse the SUPPORTED_LINK_RATES table */
> > > +    if (link_info->revision >= DP_DPCD_REV_14) {
> >
> > No, eDP has separate versioning register. DP revision != eDP revision.
>
> You're absolutely right, this was a mistake.
> Does something like this seem reasonable for v2?

Yes.

>      if (msm_dp_panel->dpcd[DP_EDP_CONFIGURATION_CAP]) {
>          u8 edp_rev;
>
>          rc = drm_dp_dpcd_read_byte(panel->aux, DP_EDP_DPCD_REV, &edp_rev);
>          if (rc)
>              return rc;
>
>          if (edp_rev >= DP_EDP_14) {
>              // parse the rates
>              // ...
>          }
>      }


--
With best wishes
Dmitry