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 <[email protected]> --- Changes in v3: - Corrected typos in the commit message (Sashiko) - Reworked HPD-related bridge locking to remove AB-BA deadlock (Jonas, Sashiko) - Link to v2: https://patch.msgid.link/[email protected] Changes in v2: - Expanded commit message, explaining difference from HDMI (Laurent) - Link to v1: https://lore.kernel.org/r/[email protected] --- Dmitry Baryshkov (3): drm/bridge: split hpd_mutex into two mutexes drm/bridge: display-connector: don't autoenable HPD IRQ drm/bridge: display-connector: trigger initial HPD event for DP drivers/gpu/drm/bridge/display-connector.c | 36 ++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_bridge.c | 16 ++++++++++--- include/drm/drm_bridge.h | 4 ++++ 3 files changed, 53 insertions(+), 3 deletions(-) --- base-commit: 687da68900cd1a46549f7d9430c7d40346cb86a0 change-id: 20260314-dp-connector-hpd-f069e66bc6af Best regards, -- With best wishes Dmitry
