Received-SPF: pass (google.com: domain of linux-kernel+bounces-42962-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Precedence: bulk
MIME-Version: 1.0
References: <20240129-x1e80100-display-v1-0-0d9eb8254df0@linaro.org> <20240129-x1e80100-display-v1-4-0d9eb8254df0@linaro.org>
In-Reply-To: <20240129-x1e80100-display-v1-4-0d9eb8254df0@linaro.org>
From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Mon, 29 Jan 2024 17:08:29 +0200
Message-ID: <CAA8EJpq1RSi4H6m6UQcyxEr=hip=ypKz9DhHziNKvDjUHsES8Q@mail.gmail.com>
Subject: Re: [PATCH 4/5] drm/msm/dp: Try looking for link-frequencies into the
 port@0's endpoint first
To: Abel Vesa <abel.vesa@linaro.org>
Cc: Rob Clark <robdclark@gmail.com>, Abhinav Kumar <quic_abhinavk@quicinc.com>, 
	Sean Paul <sean@poorly.run>, Marijn Suijten <marijn.suijten@somainline.org>, 
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>, 
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>, Maxime Ripard <mripard@kernel.org>, 
	Thomas Zimmermann <tzimmermann@suse.de>, Rob Herring <robh+dt@kernel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>, 
	Neil Armstrong <neil.armstrong@linaro.org>, linux-arm-msm@vger.kernel.org, 
	dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, 
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"

On Mon, 29 Jan 2024 at 15:19, Abel Vesa <abel.vesa@linaro.org> wrote:
>
> From: Abhinav Kumar <quic_abhinavk@quicinc.com>
>
> 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@quicinc.com>
> Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
> ---
>  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