arm_trbe_enable() records the session buffer and perf mode before __arm_trbe_enable() can fail. CoreSight skips the sink disable callback when sink enable fails, leaving that session state published even though tracing did not start.
Install buf->cpudata temporarily for the buffer setup helpers, then call __arm_trbe_enable() before assigning cpudata->buf and cpudata->mode. Clear the temporary buffer association if setup fails; the inner helper still truncates and ends the AUX transaction.
After successful enable, retain the buffer association across AUX transactions and clear it in arm_trbe_disable().
Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-trbe.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 979d0fa84c1c7b448c1ce5cd7a37dff8845795ef..9dfc6bb7afb4c42dfdec643ee7e4f2f193e2b70c 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -69,6 +69,7 @@ struct trbe_buf { int nr_pages; void **pages; bool snapshot; + /* CPU used to configure this buffer. */ struct trbe_cpudata *cpudata; };
@@ -137,6 +138,7 @@ struct trbe_save_state { * @trbe_align - Software alignment used for the TRBPTR_EL1. * @cpu - CPU this TRBE belongs to. * @mode - Mode of current operation. (perf/disabled) + * @buf - Buffer configuration retained for the enabled session. * @drvdata - TRBE specific drvdata * @errata - Bit map for the errata on this TRBE. */ @@ -1033,17 +1035,24 @@ static int arm_trbe_enable(struct coresight_device *csdev, enum cs_mode mode, struct trbe_cpudata *cpudata = dev_get_drvdata(&csdev->dev); struct perf_output_handle *handle = path->handle; struct trbe_buf *buf = etm_perf_sink_config(handle); + int ret;
WARN_ON(cpudata->cpu != smp_processor_id()); WARN_ON(cpudata->drvdata != drvdata); if (mode != CS_MODE_PERF) return -EINVAL;
- cpudata->buf = buf; - cpudata->mode = mode; + /* Buffer helpers need the CPU association while setting up tracing. */ buf->cpudata = cpudata; + ret = __arm_trbe_enable(buf, handle); + if (ret) { + buf->cpudata = NULL; + return ret; + }
- return __arm_trbe_enable(buf, handle); + cpudata->buf = buf; + cpudata->mode = mode; + return 0; }
static int arm_trbe_disable(struct coresight_device *csdev)