On 19/05/2025 6:49 pm, Leo Yan wrote:
Timestamps in the trace data appear as all zeros on recent kernels, although the feature works correctly on old kernels (e.g., v6.12).
Since commit c382ee674c8b ("arm64/sysreg/tools: Move TRFCR definitions to sysreg"), the TRFCR_ELx_TS_{VIRTUAL|GUEST_PHYSICAL|PHYSICAL} macros were updated to remove the bit shift. As a result, the driver no longer shifts bits when operates the timestamp field.
Fix this by using the FIELD_PREP() and FIELD_GET() helpers.
Reported-by: Tamas Zsoldos tamas.zsoldos@arm.com Fixes: c382ee674c8b ("arm64/sysreg/tools: Move TRFCR definitions to sysreg") Signed-off-by: Leo Yan leo.yan@arm.com
drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +- drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 6a5898355a83..acb4a58e4bb9 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1237,7 +1237,7 @@ static void cpu_detect_trace_filtering(struct etmv4_drvdata *drvdata) * tracing at the kernel EL and EL0, forcing to use the * virtual time as the timestamp. */
- trfcr = (TRFCR_EL1_TS_VIRTUAL |
- trfcr = (FIELD_PREP(TRFCR_EL1_TS_MASK, TRFCR_EL1_TS_VIRTUAL) | TRFCR_EL1_ExTRE | TRFCR_EL1_E0TRE);
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index 49d5fb87a74b..ab251865b893 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -2320,11 +2320,11 @@ static ssize_t ts_source_show(struct device *dev, goto out; }
- switch (drvdata->trfcr & TRFCR_EL1_TS_MASK) {
- val = FIELD_GET(TRFCR_EL1_TS_MASK, drvdata->trfcr);
- switch (val) { case TRFCR_EL1_TS_VIRTUAL: case TRFCR_EL1_TS_GUEST_PHYSICAL: case TRFCR_EL1_TS_PHYSICAL:
val = FIELD_GET(TRFCR_EL1_TS_MASK, drvdata->trfcr);
Reviewed-by: James Clark james.clark@linaro.org