drm/bridge: display-connector: detect DP state if cable is plugged on boot#812
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riteshk-quic merged 2 commits intoqualcomm-linux:tech/mm/drmfrom Mar 27, 2026
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If HPD IRQ is enabled in the display_connector's probe, it can be triggered too early, before the DRM connector is completely setup. Use the enable_hpd / disable_hpd callbacks to control enablement of the HPD IRQ. Fixes: 0c275c3 ("drm/bridge: Add bridge driver for display connectors") Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> Link: https://lore.kernel.org/all/20260314-dp-connector-hpd-v1-1-786044cedc17@oss.qualcomm.com/
…r DP If the DisplayPort drivers use display-connector for the HPD detection, the internal HPD state machine might be not active and thus the hardware might be not able to handle cable detection correctly. Instead it will depend on the externall HPD notifications to set the cable state, bypassing the internal HPD state machine (for example this is the case for the msm DP driver). However if the cable has been plugged before the HPD IRQ has been enabled, there will be no HPD event coming. The drivers might fail detection in such a case. Trigger the HPD notification after enabling the HPD IRQ, propagating the cable insertion state. Fixes: 2e2bf3a ("drm/bridge: display-connector: add DP support") Reported-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> Link: https://lore.kernel.org/all/20260314-dp-connector-hpd-v1-2-786044cedc17@oss.qualcomm.com/
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Unlike the USB-C AltMode handling and unlike the DP controller handling
the HPD on its own, if the display-connector is being used to handle the
HPD pin, DP controller might not be able to get either the HPD
notification nor detect the cable state if the cable is plugged in
before the system has booted.
Make the display-connector send the HPD notifications during system
startup for DisplayPort connectors.
It's typically not a problem for other types of display connectors since
there is no special procedure to detect if the monitor is actually
plugged in or not.
Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@oss.qualcomm.com
CRs-Fixed: 4455495