From 2d53bf1c4f7a887f9ea8e5ae0a50a1cec8942dec Mon Sep 17 00:00:00 2001 From: Mahadevan P Date: Fri, 17 Jul 2026 16:56:13 +0530 Subject: [PATCH] FROMLIST: drm/msm/dp: add .shutdown to mask HPD IRQ before system shutdown On reboot, a late DP hot-plug-detect (HPD) IRQ can fire after apps_smmu has already disabled translation for the display subsystem, causing the HPD thread to kick off a new modeset that drives DPU/DP hardware and DMA through a stale IOMMU mapping. DPU's own .shutdown disables all CRTCs first, but a pending HPD IRQ thread wakes up afterwards, reads the DPCD, and fires an unsolicited hotplug event that triggers a second atomic commit turning the display back on -- right as the IOMMU is disabling translation: systemd-shutdown[1]: Rebooting. msm_dpu: drm_atomic_commit: committing (shutdown disabling CRTCs) arm-smmu 3da0000.iommu: disabling translation msm_dpu: drm_dp_read_dpcd_caps (late HPD IRQ thread wakes up) msm_dpu: drm_sysfs_connector_hotplug_event: DP-1 hotplug event msm_dpu: drm_client_modeset_probe: DP-1 found preferred mode msm_dpu: drm_atomic_commit: committing (unsolicited, re-enables display) dpu_crtc_commit_kickoff: crtc94 first commit arm-smmu 15200000.iommu: disabling translation Mask and flush the IRQ in .shutdown so no HPD event can retrigger a modeset once shutdown has started. Reported on lemans-evk and monaco-evk during reboot stress testing. Link: https://lore.kernel.org/all/20260717-dpshutdown-v1-1-b062c2f7dfb1@oss.qualcomm.com/ Assisted-by: Claude:claude-sonnet-5 Signed-off-by: Mahadevan P Signed-off-by: Yash Gupta --- drivers/gpu/drm/msm/dp/dp_display.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index e06386f6bc359..7d2774eb74e77 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -1441,6 +1441,14 @@ static void msm_dp_display_remove(struct platform_device *pdev) platform_set_drvdata(pdev, NULL); } +static void msm_dp_display_shutdown(struct platform_device *pdev) +{ + struct msm_dp_display_private *dp = dev_get_dp_display_private(&pdev->dev); + + disable_irq(dp->irq); + synchronize_irq(dp->irq); +} + static int msm_dp_pm_runtime_suspend(struct device *dev) { struct msm_dp_display_private *dp = dev_get_dp_display_private(dev); @@ -1487,6 +1495,7 @@ static const struct dev_pm_ops msm_dp_pm_ops = { static struct platform_driver msm_dp_display_driver = { .probe = msm_dp_display_probe, .remove = msm_dp_display_remove, + .shutdown = msm_dp_display_shutdown, .driver = { .name = "msm-dp-display", .of_match_table = msm_dp_dt_match,