Re: [PATCH v6 1/8] drm/msm/dp: Add eDP support via aux_bus

[Doug Anderson <dianders@chromium.org>]

Hi,

On Wed, Mar 30, 2022 at 9:03 AM Sankeerth Billakanti
<quic_sbillaka@quicinc.com> wrote:
>
> @@ -1547,6 +1593,10 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
>
>         dp_display->encoder = encoder;
>
> +       ret = dp_display_get_next_bridge(dp_display);
> +       if (ret)
> +               return ret;

It feels weird to me that this is in a function called "modeset_init",
though I certainly don't know the structure of the MSM display code
well enough to fully comment. My expectation would have been that
devm_of_dp_aux_populate_ep_devices() would have been called from your
probe routine and then you would have returned -EPROBE_DEFER from your
probe if you were unable to find the panel afterwards.

Huh, but I guess you _are_ getting called (indirectly) from
dpu_kms_hw_init() and I can't imagine AUX transfers working before
that function is called, so maybe I should just accept that it's
complicated and let those who understand this driver better confirm
that it's OK. ;-)


> @@ -140,5 +140,6 @@ struct dp_parser {
>   * can be parsed using this module.
>   */
>  struct dp_parser *dp_parser_get(struct platform_device *pdev);
> +int dp_parser_find_next_bridge(struct dp_parser *parser);

Everything else in this file is described w/ kerneldoc. Shouldn't your
function also have a kerneldoc comment?