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Date:   Tue, 28 Jun 2022 23:13:56 +0300
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
To:     Kuogee Hsieh <quic_khsieh@quicinc.com>, robdclark@gmail.com,
        sean@poorly.run, swboyd@chromium.org, dianders@chromium.org,
        vkoul@kernel.org, daniel@ffwll.ch, airlied@linux.ie,
        agross@kernel.org, bjorn.andersson@linaro.org
CC:     quic_abhinavk@quicinc.com, quic_aravindh@quicinc.com,
        quic_khsieh@quicinc.com, quic_sbillaka@quicinc.com,
        freedreno@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: =?US-ASCII?Q?Re=3A_=5BPATCH=5D_drm/msm/dp=3A_make_eDP_pa?= =?US-ASCII?Q?nel_as_the_first_connected_connector?=
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On 28 June 2022 18:20:06 GMT+03:00, Kuogee Hsieh <quic_khsieh@quicinc=2Eco=
m> wrote:
>Some userspace presumes that the first connected connector is the main
>display, where it's supposed to display e=2Eg=2E the login screen=2E For
>laptops, this should be the main panel=2E
>
>This patch call drm_helper_move_panel_connectors_to_head() after
>drm_bridge_connector_init() to make sure eDP stay at head of
>connected connector list=2E This fixes unexpected corruption happen
>at eDP panel if eDP is not placed at head of connected connector
>list=2E

The change itself is a good fix anyway=2E (And I'd ack it=2E) However I wo=
uld like to understand why does it fix the corruption issue=2E What is we h=
ave eDP and DSI, with DSI ending up before the eDP? Would we see the issue?
Also could you please describe the mind of corruption you are observing?


>
>Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc=2Ecom>
>---
> drivers/gpu/drm/msm/dp/dp_drm=2Ec | 2 ++
> 1 file changed, 2 insertions(+)
>
>diff --git a/drivers/gpu/drm/msm/dp/dp_drm=2Ec b/drivers/gpu/drm/msm/dp/d=
p_drm=2Ec
>index ce0ec3a=2E=2E2d18884 100644
>--- a/drivers/gpu/drm/msm/dp/dp_drm=2Ec
>+++ b/drivers/gpu/drm/msm/dp/dp_drm=2Ec
>@@ -136,5 +136,7 @@ struct drm_connector *dp_drm_connector_init(struct ms=
m_dp *dp_display)
>=20
> 	drm_connector_attach_encoder(connector, dp_display->encoder);
>=20
>+	drm_helper_move_panel_connectors_to_head(dp_display->drm_dev);
>+
> 	return connector;
> }