PENDING: drm/msm/dp: disable HPD IRQ during shutdown to prevent IOMMU

[quicmahap]

isable HPD IRQ during shutdown to prevent crash

During system shutdown, the DP HPD interrupt can fire after the platform device has started tearing down and IOMMU translation has been disabled. The IRQ thread (msm_dp_display_irq_thread) processes the HPD event, and proceeds to access hardware registers. Because IOMMU translation is no longer active at that point, the register access causes a translation fault and a NOC decode error on the interconnect.

Fix this by disabling the IRQ at the interrupt controller before calling pm_runtime_disable() in a new .shutdown callback. synchronize_irq() is called between the two to ensure that any currently-executing instance of the IRQ thread has finished before we proceed.

After this sequence the IRQ line is masked, no new HPD events can be delivered, so no hardware access can race with the IOMMU teardown that follows.

CRs-Fixed: 4550131

[qswat-orbit-external]

Merge Check Failed: No Change Task Found

No associated change tasks found for CR 4550131 on any of the following entities:

Entities:

• kernel.qli.2.0

CR: 4550131

Please ensure the CR has a change task associated with at least one of the entities for this branch.

[qlijarvis]

PR #772 — validate-patch

PR: #772

Verdict	Issues	Detailed Report
⚠️	5	Full report

Final Summary

1. Lore link present: No — PENDING: prefix suggests patch not yet posted upstream; no lore link found in commit message
2. Lore link matches PR commits: N/A — no lore link to compare against
3. Upstream patch status: Not upstream — PENDING: prefix indicates work-in-progress; patch not found on lore.kernel.org (search attempted for drm/msm/dp shutdown fixes)
4. PR present in qcom-next: Not checked — cannot verify without kernel tree access

Verdict: ⚠️ — click to expand

🔍 Patch Validation

PR: #772 - drm/msm/dp: disable HPD IRQ during shutdown to prevent IOMMU faults
Upstream commit: N/A (PENDING: prefix indicates not yet upstream)
Verdict: ⚠️ PARTIAL

Commit Message

Check	Status	Note
Subject matches upstream	N/A	PENDING: prefix; not yet upstream
Body preserves rationale	✅	Clear problem description and fix explanation
Fixes tag present/correct	❌	Missing Fixes: tag for bug fix
Authorship preserved	⚠️	Two Signed-off-by tags; unclear if co-authored or backported
Backport note (if applicable)	N/A	Not a backport

Diff

File	Status	Notes
drivers/gpu/drm/msm/dp/dp_display.c	✅	Clean implementation; follows kernel patterns

Issues

Commit Message:

• Missing Fixes: tag — This patch fixes a race condition during shutdown causing IOMMU faults. It should include a Fixes: tag referencing the commit that introduced the vulnerable code path (likely when HPD IRQ handling was added).
• Authorship ambiguity — Two Signed-off-by tags (Jayant Shekhar, then Mahadevan P) without clear indication of co-authorship. If Jayant is the original author, the From: field should match. If Mahadevan is submitting on behalf of Jayant, a note explaining the relationship would clarify intent.
• PENDING: prefix — Indicates work-in-progress. Before merging to a stable branch, this should be removed and the patch should either be upstreamed or converted to a QCLINUX: vendor prefix if it's Qualcomm-specific.

Technical correctness:

• The fix is sound: disabling IRQ → synchronize_irq() → pm_runtime_disable() is the correct sequence to prevent race conditions.
• The shutdown callback placement in the platform_driver struct is correct.

Verdict

Do not merge as-is. Add Fixes: tag, clarify authorship, and resolve PENDING: status (upstream or convert to vendor prefix).

Final Summary

1. Lore link present: No — PENDING: prefix suggests patch not yet posted upstream; no lore link found in commit message
2. Lore link matches PR commits: N/A — no lore link to compare against
3. Upstream patch status: Not upstream — PENDING: prefix indicates work-in-progress; patch not found on lore.kernel.org (search attempted for drm/msm/dp shutdown fixes)
4. PR present in qcom-next: Not checked — cannot verify without kernel tree access

[qlijarvis]

PR #772 — checker-log-analyzer

PR: #772
Checker run: https://github.com/qualcomm-linux/kernel-config/actions/runs/28153080250

Checker	Result	Summary
Checker	Result	Summary
checkpatch	✅	No style issues detected
dt-binding-check	⏭️	Skipped - no devicetree binding changes
dtb-check	⏭️	Skipped - no devicetree changes
sparse-check	✅	No sparse warnings
check-uapi-headers	✅	No UAPI header changes
check-patch-compliance	❌	Subject prefix violation
tag-check	N/A	Not applicable for qcom-6.18.y branch
qcom-next-check	N/A	Not applicable for qcom-6.18.y branch

Detailed report: Full report

Checker analysis — click to expand

🤖 CI Checker Analysis (checker-log-analyzer)

PR: #772 - PENDING: drm/msm/dp: disable HPD IRQ during shutdown to prevent IOMMU faults
Source: https://github.com/qualcomm-linux/kernel-config/actions/runs/28153080250

Checker	Result	Summary
checkpatch	✅	No style issues detected
dt-binding-check	⏭️	Skipped - no devicetree binding changes
dtb-check	⏭️	Skipped - no devicetree changes
sparse-check	✅	No sparse warnings
check-uapi-headers	✅	No UAPI header changes
check-patch-compliance	❌	Subject prefix violation
tag-check	N/A	Not applicable for qcom-6.18.y branch
qcom-next-check	N/A	Not applicable for qcom-6.18.y branch

❌ check-patch-compliance

Root cause: Commit subject starts with PENDING: prefix, which is not a recognized upstream or backport prefix.

Failure details:

Checking commit: PENDING: drm/msm/dp: disable HPD IRQ during shutdown to prevent IOMMU faults
Commit summary does not start with a required prefix

Fix: Replace the PENDING: prefix with one of the following required prefixes:

1. If this is a new patch awaiting upstream submission:

   • Use FROMLIST: prefix (indicates patch is posted to a mailing list but not yet merged)
   • Example: FROMLIST: drm/msm/dp: disable HPD IRQ during shutdown to prevent IOMMU faults

2. If this patch is already merged upstream:

   • Use UPSTREAM: prefix
   • Example: UPSTREAM: drm/msm/dp: disable HPD IRQ during shutdown to prevent IOMMU faults

3. If this is a Qualcomm-specific patch not intended for upstream:

   • Use QCOM: prefix
   • Example: QCOM: drm/msm/dp: disable HPD IRQ during shutdown to prevent IOMMU faults

4. If this is a backport from a stable kernel:

   • Use BACKPORT: prefix
   • Example: BACKPORT: drm/msm/dp: disable HPD IRQ during shutdown to prevent IOMMU faults

Reproduce locally:

cd /path/to/kernel
git log -1 --format=%s 02ce804404e7499f12b9a5caa6cd4d805068bcc5
# Check if subject starts with UPSTREAM:, FROMLIST:, BACKPORT:, or QCOM:

To fix the commit:

git rebase -i HEAD~1
# Change 'pick' to 'reword' for the commit
# Update the subject line to use the appropriate prefix

Verdict

1 blocker to fix: The commit subject must use a compliant prefix (UPSTREAM:, FROMLIST:, BACKPORT:, or QCOM:) instead of PENDING:. All other checkers passed successfully. Once the subject prefix is corrected, this PR will be ready to merge.

[qcomlnxci]

Test jobs on 02ce804

• Job 142545 on lemans-evk
• Job 142541 on monaco-evk
• Job 142540 on qcs615-ride
• Job 142543 on qcs6490-rb3gen2
• Job 142546 on qcs8300-ride
• Job 142544 on qcs9100-ride-r3
• Job 142542 on x1e80100-crd

[qcomlnxci]

Test Matrix

Test Case	lemans-evk	monaco-evk	qcs615-ride	qcs6490-rb3gen2	qcs8300-ride	qcs9100-ride-r3	x1e80100-crd
BT_FW_KMD_Service	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
BT_ON_OFF	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
BT_SCAN	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
CPUFreq_Validation	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
CPU_affinity	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
DSP_AudioPD	✅ Pass	✅ Pass	⚠️ skip	✅ Pass	✅ Pass	⚠️ skip	◻️
Ethernet	⚠️ skip	✅ Pass	⚠️ skip	⚠️ skip	⚠️ skip	⚠️ skip	◻️
Freq_Scaling	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
GIC	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
IPA	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
Interrupts	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
OpenCV	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
PCIe	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
Probe_Failure_Check	❌ Fail	❌ Fail	❌ Fail	❌ Fail	❌ Fail	❌ Fail	◻️
RMNET	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
UFS_Validation	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
USBHost	❌ Fail	❌ Fail	❌ Fail	❌ Fail	❌ Fail	❌ Fail	◻️
WiFi_Firmware_Driver	❌ Fail	❌ Fail	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
WiFi_OnOff	✅ Pass	❌ Fail	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
adsp_remoteproc	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	❌ Fail	◻️
cdsp_remoteproc	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	❌ Fail	◻️
gpdsp_remoteproc	✅ Pass	✅ Pass	⚠️ skip	⚠️ skip	✅ Pass	❌ Fail	◻️
hotplug	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
irq	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
kaslr	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
pinctrl	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
qcom_hwrng	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
remoteproc	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	❌ Fail	◻️
rngtest	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
shmbridge	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
smmu	❌ Fail	✅ Pass	❌ Fail	✅ Pass	✅ Pass	❌ Fail	◻️
watchdog	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️
wpss_remoteproc	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	✅ Pass	◻️

[quicmahap]

Exception jira: https://jira-dc.qualcomm.com/jira/browse/QLIJIRA-144