QCLINUX: arm64: configs: qcom: reduce SWIOTLB size to 2 MiB

[Jagadeesh Pagadala (jpagadal)]

Set CONFIG_SWIOTLB_DEFAULT_SIZE_MB=2 to reduce the default SWIOTLB pool size from 64 MiB to 2 MiB.

This lowers kernel reserved memory and increases available RAM for user space.

CRs-Fixed: 4490764

Corresponding mainline change: qualcomm-linux/kernel-topics#1644

Validation:
Boot verified on RB3 Gen2, IQ8.
SWIOTLB pool reduced from 64 MiB to 2 MiB.

[qlijarvis]

PR #906 — validate-patch

PR: #906

Verdict	Issues	Detailed Report
⚠️	1	Full report

Final Summary

1. Lore link present: No — QCLINUX: prefix; no lore link expected or required
2. Lore link matches PR commits: N/A — no lore link to compare against
3. Upstream patch status: N/A — vendor-only change, not posted upstream
4. PR present in qcom-next/topics: Fail - 1/1 commit(s) are missing from both qcom-next and topics

Verdict: ⚠️ — click to expand

🔍 Patch Validation

PR: #906 - QCLINUX: arm64: configs: qcom: reduce SWIOTLB size to 2 MiB
Upstream commit: N/A (vendor-only change)
Verdict: ⚠️ PARTIAL

Commit Message

Check	Status	Note
Subject matches upstream	N/A	QCLINUX: vendor-only commit
Body preserves rationale	✅	Clear explanation of memory optimization
Fixes tag present/correct	N/A	Not a fix
Authorship preserved	✅	Consistent author and sign-off
Backport note (if applicable)	N/A	Not a backport

Diff

File	Status	Notes
arch/arm64/configs/qcom.config	✅	Single-line config addition, clean and focused

Issues

• ⚠️ Integration presence: Commit is missing from both qcom-next and all topic branches. For a vendor-specific config change, this is unexpected — typically QCLINUX: commits should be present in the integration tree before PR submission.

Verdict

The patch itself is technically correct and well-formed. However, the absence from qcom-next/topics suggests this may be a new change that hasn't been integrated yet. Verify integration status before merging.

Final Summary

1. Lore link present: No — QCLINUX: prefix; no lore link expected or required
2. Lore link matches PR commits: N/A — no lore link to compare against
3. Upstream patch status: N/A — vendor-only change, not posted upstream
4. PR present in qcom-next/topics: Fail — 1/1 commit(s) are missing from both qcom-next and topics (per integration_presence_report.md)

Deterministic Integration Presence

Integration Presence Report

This report is generated by Jarvis before validate-patch runs.
It is the authoritative source for whether PR changes are already present
in qcom-next or in the kernel topic branches.

Kernel repo: /local/mnt/workspace/sgaud/Qgenie/image_pipeline/kernel
qcom-next ref: 8d5dbc1b17adf8fe86a41adcda686785e73f5414
topics remote: topics -> https://github.com/qualcomm-linux/kernel-topics
topics fetch: fetched

Commit	Subject	qcom-next	topics	Final
1/1	[PATCH] QCLINUX: arm64: configs: qcom: reduce SWIOTLB size to 2 MiB	missing - no subject, patch-id, or full tree-content match found	missing - no subject, patch-id, or full tree-content match found	missing

Final Status

overall_status: FAIL
present_commits: 0/1
partial_commits: 0/1
missing_commits: 1/1
topics_checked_for_commits: 1/1
final_summary: PR present in qcom-next/topics: Fail - 1/1 commit(s) are missing from both qcom-next and topics

[qlijarvis]

PR #906 — checker-log-analyzer

PR: #906
Checker run: https://github.com/qualcomm-linux/kernel-config/actions/runs/31072200744

Checker	Result	Summary
Checker	Result	Summary
checkpatch	✅	0 errors, 0 warnings, 0 checks
dt-binding-check	⏭️	No changes in Documentation/devicetree/bindings
dtb-check	⏭️	No changes in Devicetree
sparse-check	⏭️	Skipping sparse check as nothing changed
check-uapi-headers	⏭️	Skipping uapi check as nothing changed
check-patch-compliance	❌	Prefix validation failed
tag-check	❌	QCLINUX: prefix used (valid for tag-check but fails check-patch-compliance)

Detailed report: Full report

Checker analysis — click to expand

🤖 CI Checker Analysis (checker-log-analyzer)

PR: #906 - QCLINUX: arm64: configs: qcom: reduce SWIOTLB size to 2 MiB
Target branch: qcom-6.18.y
Source: https://github.com/qualcomm-linux/kernel-config/actions/runs/31072200744

Checker	Result	Summary
checkpatch	✅	0 errors, 0 warnings, 0 checks
dt-binding-check	⏭️	No changes in Documentation/devicetree/bindings
dtb-check	⏭️	No changes in Devicetree
sparse-check	⏭️	Skipping sparse check as nothing changed
check-uapi-headers	⏭️	Skipping uapi check as nothing changed
check-patch-compliance	❌	Prefix validation failed
tag-check	❌	QCLINUX: prefix used (valid for tag-check but fails check-patch-compliance)

---

❌ check-patch-compliance

Root cause: The commit uses QCLINUX: prefix, which is not in the allowed list for check-patch-compliance.

Failure details:

Checking commit: QCLINUX: arm64: configs: qcom: reduce SWIOTLB size to 2 MiB
Commit summary does not start with a required prefix

Analysis:

The check-patch-compliance checker only accepts these prefixes:

• FROMLIST: — Patch posted to mailing list (lore.kernel.org)
• FROMGIT: — Patch taken from a maintainer git tree
• UPSTREAM: — Patch merged into Linus's mainline tree
• BACKPORT: — Upstream patch backported with modifications

The commit uses QCLINUX:, which is a vendor-internal prefix used in the Qualcomm Linux tree for vendor-only changes with no upstream equivalent. This prefix is not accepted by check-patch-compliance.

This is a known limitation of the checker — vendor-only commits with QCLINUX: or PENDING: prefixes will always fail check-patch-compliance because the checker enforces upstream-linkable prefixes only.

Context:

• This is a config-only change (CONFIG_SWIOTLB_DEFAULT_SIZE_MB=2) that reduces SWIOTLB pool size from 64 MiB to 2 MiB.
• The change is vendor-specific and has no upstream equivalent (it's a Qualcomm-specific tuning decision).
• The QCLINUX: prefix is appropriate for this type of change in the Qualcomm Linux tree.

Options:

1. Accept the checker failure — This is a known limitation. The QCLINUX: prefix is correct for vendor-only changes. The checker will always fail for such commits.

2. Change to FROMLIST: + add Link — Only if this change has been posted upstream (which is unlikely for a vendor-specific config tuning). This would require:

   git commit --amend -m "FROMLIST: arm64: configs: qcom: reduce SWIOTLB size to 2 MiB
   
   Set CONFIG_SWIOTLB_DEFAULT_SIZE_MB=2 to reduce the default
   SWIOTLB pool size from 64 MiB to 2 MiB.
   
   This lowers kernel reserved memory and increases available
   RAM for user space.
   
   Link: https://lore.kernel.org/...
   Signed-off-by: Jagadeesh Pagadala <jpagadal@qti.qualcomm.com>"

3. Remove the prefix entirely — Not recommended, as the target branch qcom-6.18.y requires a prefix tag (see tag-check below).

Reproduce locally:

cd kernel
bash ../kernel-checkers/check-patch-compliance.sh \
  --kernel-src . \
  --base 8635749eab9a8a3a2e3533b2077d70c8b16857ba \
  --head 3ea7a82d33430549b62ee2836cc730729b0ca9d6

---

✅ tag-check

Status: PASS (with caveat)

Analysis:

The target branch is qcom-6.18.y, which is not qcom-next or qcom-next-staging. Therefore, every commit must start with a valid subject prefix.

The commit subject is:

QCLINUX: arm64: configs: qcom: reduce SWIOTLB size to 2 MiB

The QCLINUX: prefix is a valid prefix for the tag-check (it's in the allowed list: FROMLIST:, FROMGIT:, UPSTREAM:, BACKPORT:, QCLINUX:, PENDING:, WORKAROUND:).

Verdict: ✅ PASS — The commit has a valid subject prefix for the target branch.

Note: While tag-check passes, check-patch-compliance fails because it enforces a stricter subset of prefixes (only upstream-linkable ones). This is a known discrepancy between the two checks.

---

Verdict

1 blocker (check-patch-compliance) — known limitation for vendor-only commits.

Recommendation:

• If this is a vendor-only change with no upstream equivalent: Accept the check-patch-compliance failure. The QCLINUX: prefix is correct and appropriate. This is a known limitation of the checker.

• If this change should be posted upstream: Change the prefix to FROMLIST: and add a Link: trailer pointing to the lore.kernel.org URL after posting.

All other checkers passed or were correctly skipped (no relevant files changed). The patch itself is clean — no coding style issues, no DT/binding changes, no sparse warnings, no UAPI changes.