On Sun, Feb 26, 2023 at 09:04:16PM -0500, Sasha Levin wrote: > From: Bjorn Andersson <quic_bjorande@xxxxxxxxxxx> > > [ Upstream commit e17af1c9d861dc177e5b56009bd4f71ace688d97 ] > > 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@xxxxxxxxxxx> > Reviewed-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> > Patchwork: https://patchwork.freedesktop.org/patch/518729/ > Link: https://lore.kernel.org/r/20230117172951.2748456-1-quic_bjorande@xxxxxxxxxxx > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> This is not a bug fix and should not be backported. Johan
