drm/msm/dp: Remove INIT_SETUP delay
authorBjorn Andersson <quic_bjorande@quicinc.com>
Tue, 17 Jan 2023 17:29:51 +0000 (09:29 -0800)
committerDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Wed, 18 Jan 2023 01:45:14 +0000 (03:45 +0200)
commite17af1c9d861dc177e5b56009bd4f71ace688d97
tree79557c015c36159995feb2c9230a530245a2e6cb
parent0e7f270591a42f6c674d2410ac30e086ea0bf54d
drm/msm/dp: Remove INIT_SETUP delay

During initalization of the DisplayPort controller an EV_HPD_INIT_SETUP
event is generated, but with a delay of 100 units. This delay existed to
circumvent bug in the QMP combo PHY driver, where if the DP part was
powered up before USB, the common properties would not be properly
initialized - and USB wouldn't work.

This issue was resolved in the recent refactoring of the QMP driver,
so it's now possible to remove this delay.

While there is still a timing dependency in the current implementation,
test indicates that it's now possible to boot with an external display
on USB Type-C and have the display power up, without disconnecting and
reconnecting the cable.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/518729/
Link: https://lore.kernel.org/r/20230117172951.2748456-1-quic_bjorande@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
drivers/gpu/drm/msm/dp/dp_display.c