[PATCH 0/2] fix inconsistencies with sysfs configuration in etm
From: Yeoreum Yun
Date: Tue Mar 17 2026 - 14:17:18 EST
The current ETMx configuration via sysfs can lead to the following
inconsistencies:
- If a configuration is modified via sysfs while a perf session is
active, the running configuration may differ between before
a sched-out and after a subsequent sched-in.
- Once a perf session is enabled, some read-only register fields
(e.g., TRCSSCSR<n>) may not be reported correctly,
because drvdata->config is cleared while enabling with perf mode,
even though the information was previously read.
To resolve these inconsistencies, the configuration should be separated into:
- active_config, which represents the currently applied configuration
- config, which stores the settings configured via sysfs.
This patch based on v7.0-rc4
Yeoreum Yun (2):
coresight: etm4x: fix inconsistencies with sysfs configration
coresight: etm3x: fix inconsistencies with sysfs configration
drivers/hwtracing/coresight/coresight-etm.h | 2 +
.../coresight/coresight-etm3x-core.c | 11 +++--
.../hwtracing/coresight/coresight-etm4x-cfg.c | 2 +-
.../coresight/coresight-etm4x-core.c | 45 +++++++++++--------
drivers/hwtracing/coresight/coresight-etm4x.h | 2 +
5 files changed, 39 insertions(+), 23 deletions(-)
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