On eDP interfaces with no panel connected, panel-simple-dp-aux fails to read DPCD over AUX during probe, leaving hpd_state at ST_DISCONNECTED. msm_dp_bridge_atomic_enable() exits early as a result, so msm_dp_display_enable() is never called and power_on remains false with link clocks never enabled.
During system suspend, drm_atomic_helper_suspend() still invokes atomic_disable() for all registered bridges. The resulting write to REG_DP_STATE_CTRL against an unpowered controller triggers a NoC slave error, causing a fatal crash. Guard push_idle with a power_on check to skip the register access when the display was never enabled. Signed-off-by: Yongxing Mou <[email protected]> --- drivers/gpu/drm/msm/dp/dp_display.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index 1b3cbf4016ef..51b60eb9c2df 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -1660,6 +1660,13 @@ void msm_dp_bridge_atomic_disable(struct drm_bridge *drm_bridge, msm_dp_display = container_of(dp, struct msm_dp_display_private, msm_dp_display); + /* + * push_idle accesses link registers which require link clocks to be on. + * Skip if the display was never powered on (e.g. eDP with no panel). + */ + if (!dp->power_on) + return; + msm_dp_ctrl_push_idle(msm_dp_display->ctrl); } --- base-commit: e98d21c170b01ddef366f023bbfcf6b31509fa83 change-id: 20260511-edp_suspend-0e45d0110633 Best regards, -- Yongxing Mou <[email protected]>
