iommu/arm-smmu: Add interconnect bandwidth voting support by bibekpatro · Pull Request #590 · qualcomm-linux/kernel

bibekpatro · 2026-05-16T12:56:03Z

iommu/arm-smmu: Add interconnect bandwidth voting support

Link: https://lore.kernel.org/all/20260516-smmu_interconnect_addition-v1-0-f889d933f5c1@oss.qualcomm.com/#t

CRs-Fixed: 4523338

qswat-orbit-external · 2026-05-16T12:56:10Z

Merge Check Failed: No Change Task Found

No associated change tasks found for CR 4523338 on any of the following entities:

Entities:

kernel.qli.2.0

CR: 4523338

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

shashim-quic

Add Link: tag pointing to lore link in your commit log.

sgaud-quic · 2026-05-18T05:01:58Z

PR #590 — validate-patch

PR: #590

Verdict	Issues	Detailed Report
❌	0	Full report

Verdict: ❌ — click to expand

🔍 Patch Validation

PR: qualcomm-linux/kernel #590 — 2 commits: FROMLIST: dt-bindings: iommu: arm,smmu: Document optional interconnects property + FROMLIST: iommu/arm-smmu: Add interconnect bandwidth voting support
Upstream commit: ❌ No Link: tag found in either commit
Verdict: ❌ FAIL

Step 1 — Lore Link Check

Both commits carry the FROMLIST: prefix, which requires a Link: https://lore.kernel.org/r/<message-id> tag. Neither commit contains one. Network access is unavailable in this environment, so lore.kernel.org cannot be queried to locate the postings independently.

Commit 1 (51541a78a199): FROMLIST: dt-bindings: iommu: arm,smmu: Document optional interconnects property — no Link tag

Commit 2 (f0764e9f6b25): FROMLIST: iommu/arm-smmu: Add interconnect bandwidth voting support — no Link tag

Because no lore URL is present, Steps 2, 5, 7, 8, 9 (diff comparison against upstream) cannot be performed.

Commit Message

Check Commit 1 (dt-bindings) Commit 2 (arm-smmu.c/.h)

FROMLIST: prefix present ✅ ✅

Link: tag present ❌ Missing ❌ Missing

Subject line well-formed ✅ ✅

Body preserves rationale ✅ Adequate ✅ Adequate

Fixes: tag N/A (new feature) N/A (new feature)

Original author Signed-off-by: ✅ bibek.patro@oss.qualcomm.com ✅ bibek.patro@oss.qualcomm.com

Co-developed-by: misuse N/A N/A

Backport note N/A N/A

Diff

File Status Notes

Documentation/devicetree/bindings/iommu/arm,smmu.yaml ⚠️ REVIEW Cannot compare to lore (no Link tag). Content self-consistent: adds interconnects with maxItems: 1 and description.

drivers/iommu/arm/arm-smmu/arm-smmu.c ⚠️ REVIEW Cannot compare to lore. Logic coherent: icc_get/icc_enable/icc_disable helpers added; called in probe, runtime_resume, runtime_suspend. See issue #3 below.

drivers/iommu/arm/arm-smmu/arm-smmu.h ⚠️ REVIEW Cannot compare to lore. Adds #include <linux/interconnect.h> and icc_path field to arm_smmu_device — correct.

Upstream Patch Status

Commit Community Verdict

dt-bindings: iommu: arm,smmu: Document optional interconnects property ⏳ Decision Pending — no lore link; network unavailable; cannot verify mailing-list status

iommu/arm-smmu: Add interconnect bandwidth voting support ⏳ Decision Pending — no lore link; network unavailable; cannot verify mailing-list status

qcom-next Presence

Commit Status

FROMLIST: dt-bindings: iommu: arm,smmu: Document optional interconnects property ⏭️ Skipped — network access unavailable; verify manually

FROMLIST: iommu/arm-smmu: Add interconnect bandwidth voting support ⏭️ Skipped — network access unavailable; verify manually

Issues
Missing Link: tag — Commit 1 (51541a78a199): FROMLIST: commits must include Link: https://lore.kernel.org/r/<message-id>. Without it the patch cannot be traced to its upstream origin and check-patch-compliance CI fails.

Missing Link: tag — Commit 2 (f0764e9f6b25): Same as issue Create qualcomm-linux-organization-repolinter.yml #1.
ICC vote leaked on probe error path — Commit 2: In arm_smmu_device_probe, arm_smmu_icc_enable() is called before arm_smmu_device_cfg_probe(). If arm_smmu_device_cfg_probe() (or any subsequent step) returns an error, the function returns without calling arm_smmu_icc_disable(), leaving the interconnect bandwidth vote active. All error-return paths after arm_smmu_icc_enable() in probe should call arm_smmu_icc_disable() before returning.
 err = arm_smmu_device_cfg_probe(smmu);
-	if (err)
-		return err;
+	if (err) {
+		arm_smmu_icc_disable(smmu);
+		return err;
+	}
(And similarly for any further error returns in the probe function after this point.)
Verdict

Do not merge. Both commits must be amended to add a Link: https://lore.kernel.org/r/<message-id> tag pointing to the mailing-list posting before this PR can be validated or merged. Additionally, the ICC vote leak on probe error paths in Commit 2 should be fixed. Recommended actions:

Post (or confirm posting of) both patches to linux-iommu@lists.linux.dev and devicetree@vger.kernel.org.

Obtain the lore message-ID for each patch and amend each commit to add the Link: line.

Fix the missing arm_smmu_icc_disable() call on all error-return paths in arm_smmu_device_probe() after arm_smmu_icc_enable() is called.

Force-push and re-run CI.

sgaud-quic · 2026-05-18T05:02:00Z

PR #590 — checker-log-analyzer

PR: #590
Checker run: https://github.com/qualcomm-linux/kernel-config/actions/runs/25962535905

Checker	Result	Summary
Checker	Result	Summary
checkpatch	✅	0 errors, 0 warnings on both commits
dt-binding-check	✅	`dt_binding_check` and `dtbs_check` passed for `arm,smmu.yaml`
dtb-check	⏭️	No changes in Devicetree — skipped
sparse-check	✅	No new sparse errors introduced by PR
check-uapi-headers	✅	No changes to UAPI headers
check-patch-compliance	❌	Both commits missing `Link:` tag
tag-check	✅	Both commits carry `FROMLIST:` prefix — satisfies requirement
qcom-next-check	N/A	PR targets `qcom-6.18.y`, not `qcom-next`

Detailed report: Full report

Checker analysis — click to expand

🤖 CI Checker Analysis (checker-log-analyzer)

PR: FROMLIST: iommu/arm-smmu: Add interconnect bandwidth voting support — #590
Source: https://github.com/qualcomm-linux/kernel-config/actions/runs/25962535905
Target branch: qcom-6.18.y (base SHA: 6964936c9bfc, head SHA: f0764e9f6b25)

Checker Result Summary

checkpatch ✅ 0 errors, 0 warnings on both commits

dt-binding-check ✅ dt_binding_check and dtbs_check passed for arm,smmu.yaml

dtb-check ⏭️ No changes in Devicetree — skipped

sparse-check ✅ No new sparse errors introduced by PR

check-uapi-headers ✅ No changes to UAPI headers

check-patch-compliance ❌ Both commits missing Link: tag

tag-check ✅ Both commits carry FROMLIST: prefix — satisfies requirement

qcom-next-check N/A PR targets qcom-6.18.y, not qcom-next

❌ check-patch-compliance

Root cause: Both FROMLIST: commits are missing a Link: trailer pointing to the upstream lore.kernel.org message, which is required for all FROMLIST: patches.

Failure details:
Checking commit: FROMLIST: dt-bindings: iommu: arm,smmu: Document optional interconnects property
No 'Link' found in commit message

Checking commit: FROMLIST: iommu/arm-smmu: Add interconnect bandwidth voting support
No 'Link' found in commit message

##[error]Process completed with exit code 1.
Fix: Add a Link: trailer to each commit pointing to the upstream lore.kernel.org thread. Find the correct lore URL for each patch (e.g. via b4 search or the mailing list archive), then amend both commits:
# For commit 1 (dt-bindings patch):
git rebase -i 6964936c9bfc
# mark 51541a78a199 as 'edit'
git commit --amend
# Add to commit body:
#   Link: https://lore.kernel.org/r/<message-id>
git rebase --continue

# For commit 2 (arm-smmu driver patch):
# mark f0764e9f6b25 as 'edit'
git commit --amend
# Add to commit body:
#   Link: https://lore.kernel.org/r/<message-id>
git rebase --continue
Reproduce locally:
bash kernel-checkers/check-patch-compliance.sh \
  --kernel-src <path/to/kernel> \
  --base 6964936c9bfc3337aa8ba8a0fb25021d06e5ce04 \
  --head f0764e9f6b253c50d16ad236cf4d39571bc7ed86
Verdict

1 blocker to fix before merge: add Link: https://lore.kernel.org/r/<message-id> to both FROMLIST: commits (51541a78a199 and f0764e9f6b25). All other checkers pass or are not applicable.

…ts property Some SoC implementations require a bandwidth vote on an interconnect path before the SMMU register space is accessible. Add the optional 'interconnects' property to the binding to allow platform DT nodes to describe this path. The arm-smmu driver uses these properties to vote for bandwidth before accessing any SMMU registers and releases the vote on runtime suspend. Link: https://lore.kernel.org/all/20260516-smmu_interconnect_addition-v1-1-f889d933f5c1@oss.qualcomm.com/ Signed-off-by: Bibek Kumar Patro <bibek.patro@oss.qualcomm.com>

On some SoCs the SMMU registers require an active interconnect bandwidth vote to be accessible. While other clients typically satisfy this requirement implicitly, certain corner cases (e.g. during sleep/wakeup transitions) can leave the SMMU without a vote, causing intermittent register access failures. Add support for an optional interconnect path to the arm-smmu driver and vote for bandwidth while the SMMU is active. The path is acquired from DT if present and ignored otherwise. The bandwidth vote is enabled before accessing SMMU registers during probe and runtime resume, and released during runtime suspend and on error paths. Generally, from an architectural perspective, GEM_NOC and DDR are expected to have an active vote whenever the adreno_smmu block is powered on. In most common use cases, this requirement is implicitly satisfied because other GPU-related clients (for example, the GMU device) already hold a GEM_NOC vote when adreno_smmu is enabled. However, there are certain corner cases, such as during sleep/wakeup transitions, where the GEM_NOC vote can be removed before adreno_smmu is powered down. If adreno_smmu is then accessed while the interconnect vote is missing, it can lead to the observed failures. Because of the precise ordering involved, this scenario is difficult to reproduce consistently. (also GDSC is involved in adreno usecases can have an independent vote) Link: https://lore.kernel.org/all/20260516-smmu_interconnect_addition-v1-2-f889d933f5c1@oss.qualcomm.com/ Signed-off-by: Bibek Kumar Patro <bibek.patro@oss.qualcomm.com>

qswat-orbit-external · 2026-05-18T05:33:33Z

Merge Check Failed: No Change Task Found

No associated change tasks found for CR 4523338 on any of the following entities:

Entities:

kernel.qli.2.0

CR: 4523338

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

bibekpatro · 2026-05-18T05:35:22Z

Add Link: tag pointing to lore link in your commit log.

Addressed for both the commits now.

shashim-quic

Diff and code quality look good. Both commits show committer == author (bibek.patro@oss.qualcomm.com). Please have a separate integrator commit/sign off before merging.

bibekpatro requested review from a team, Komal-Bajaj, quic-kaushalk and trsoni May 16, 2026 12:56

bibekpatro mentioned this pull request May 16, 2026

iommu/arm-smmu: Add interconnect bandwidth voting support #575

Closed

shashim-quic requested changes May 18, 2026

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bibekpatro added 2 commits May 18, 2026 11:00

bibekpatro force-pushed the qcom-6.18.y branch from f0764e9 to c06334f Compare May 18, 2026 05:33

qcomlnxci requested a review from a team May 18, 2026 05:37

shashim-quic reviewed May 19, 2026

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iommu/arm-smmu: Add interconnect bandwidth voting support#590

iommu/arm-smmu: Add interconnect bandwidth voting support#590
bibekpatro wants to merge 2 commits into
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bibekpatro commented May 16, 2026

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sgaud-quic commented May 18, 2026

🔍 Patch Validation

Step 1 — Lore Link Check

Commit Message

Diff

Upstream Patch Status

qcom-next Presence

Issues

Verdict

Uh oh!

sgaud-quic commented May 18, 2026

🤖 CI Checker Analysis (checker-log-analyzer)

❌ check-patch-compliance

Verdict

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sgaud-quic commented May 18, 2026

PR #590 — validate-patch

🔍 Patch Validation

Step 1 — Lore Link Check

Commit Message

Diff

Upstream Patch Status

qcom-next Presence

Issues

Verdict

Uh oh!

sgaud-quic commented May 18, 2026

PR #590 — checker-log-analyzer

🤖 CI Checker Analysis (checker-log-analyzer)

❌ check-patch-compliance

Verdict

Uh oh!

qswat-orbit-external Bot commented May 18, 2026

Uh oh!

bibekpatro commented May 18, 2026

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