Optimize the Coresight Trace id allocation logic - #1032
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Jie Gan (jiegan0107) wants to merge 2 commits into
Open
Optimize the Coresight Trace id allocation logic#1032Jie Gan (jiegan0107) wants to merge 2 commits into
Jie Gan (jiegan0107) wants to merge 2 commits into
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When coresight_path_assign_trace_id() cannot assign a valid trace ID, coresight_enable_sysfs() takes the err_path goto with ret still 0, returning success to the caller despite no trace session being started. Change coresight_path_assign_trace_id() to return int, moving the IS_VALID_CS_TRACE_ID() check inside it so it returns -EINVAL on failure and 0 on success. Update both callers to propagate this return value directly instead of inspecting path->trace_id after the call. Fixes: d87d76d ("Coresight: Allocate trace ID after building the path") Reviewed-by: James Clark <james.clark@linaro.org> Reviewed-by: Richard Cheng <icheng@nvidia.com> Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com> Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20260512-fix-trace-id-error-v4-1-eb3de789767a@oss.qualcomm.com
…vices coresight_path_assign_trace_id() only treats a trace_id of 0 as "this device has no ID assignment, keep searching downstream". Pass-through NoC links such as itnoc (qcom,coresight-itnoc) intentionally return -EOPNOTSUPP from their .trace_id callback since they have no ATID register to program, but that negative value falls through to the IS_VALID_CS_TRACE_ID() check and is rejected, aborting the whole path with -EINVAL before the real trace ID owner further downstream is ever reached. This breaks enabling any source whose path traverses an itnoc, e.g. writing 1 to tpdm/enable_source for a TPDM fails with: sh: write error: Invalid argument Skip devices that return -EOPNOTSUPP the same way as devices that return 0, so the search continues to the next device on the path. Fixes: f4526ff ("coresight: fix missing error code when trace ID is invalid") Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com> Link: https://lore.kernel.org/all/20260817-fix-trace-id-assign-issue-v1-1-b2164e33f9fa@oss.qualcomm.com/
Jie Gan (jiegan0107)
requested review from
a team,
Amit Kucheria (idlethread),
jingyiwang42 and
Kaushal Kumar (quic-kaushalk)
August 31, 2026 02:42
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Optimize the Coresight Trace id allocation logic
CRs-Fixed: 4661884