Re: [PATCH 4/5] drm/msm/dp: Try looking for link-frequencies into the port@0's endpoint first

From: Dmitry Baryshkov
Date: Mon Jan 29 2024 - 10:09:01 EST


On Mon, 29 Jan 2024 at 15:19, Abel Vesa <abel.vesa@xxxxxxxxxx> wrote:
>
> From: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
>
> On platforms where the endpoint used is on port@0, looking for port@1
> instead results in just ignoring the max link-frequencies altogether.
> Look at port@0 first, then, if not found, look for port@1.

NAK. Platforms do not "use port@0". It is for the connection between
DPU and DP, while the link-frequencies property is for the link
between DP controller and the actual display.

>
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/dp/dp_parser.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c
> index 7032dcc8842b..eec5b8b83f4b 100644
> --- a/drivers/gpu/drm/msm/dp/dp_parser.c
> +++ b/drivers/gpu/drm/msm/dp/dp_parser.c
> @@ -97,7 +97,11 @@ static u32 dp_parser_link_frequencies(struct device_node *of_node)
> u64 frequency = 0;
> int cnt;
>
> - endpoint = of_graph_get_endpoint_by_regs(of_node, 1, 0); /* port@1 */
> + endpoint = of_graph_get_endpoint_by_regs(of_node, 0, 0); /* port@0 */
> +
> + if (!endpoint)
> + endpoint = of_graph_get_endpoint_by_regs(of_node, 1, 0); /* port@1 */
> +
> if (!endpoint)
> return 0;
>
>
> --
> 2.34.1
>


--
With best wishes
Dmitry