drm/msm/dp: rework HPD handling

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Handling of the HPD events in the MSM DP driver is plagued with lots of
problems. It tries to work aside of the main DRM framework, handling the
HPD signals on its own. There are two separate paths, one for the HPD
signals coming from the DP HPD pin and another path for signals coming
from outside (e.g. from the Type-C AltMode). It lies about the connected
state, returning the link established state instead. It is not easy to
understand or modify it. Having a separate event machine doesn't add
extra clarity.

Drop the whole event machine. When the DP receives a HPD event, send it
to the DRM core. Then handle the events in the hpd_notify callback,
unifying paths for HPD signals.

Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Co-developed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727616/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-7-cf3ab488dd7b@oss.qualcomm.com

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This commit is contained in:

Jessica Zhang 2026-05-24 13:33:35 +03:00 • committed by Dmitry Baryshkov

parent c5d65a2b48

commit 5043357e75

4 changed files with 134 additions and 485 deletions

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16

drivers/gpu/drm/msm/dp/dp_ctrl.c

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1

drivers/gpu/drm/msm/dp/dp_ctrl.h

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601

drivers/gpu/drm/msm/dp/dp_display.c

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1

drivers/gpu/drm/msm/dp/dp_display.h

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