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authorSuzuki K Poulose <suzuki.poulose@arm.com>2018-09-20 13:17:52 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-25 20:09:17 +0200
commitcad5f8d399bbe3c4ed61a21f649d61b09f6efb7b (patch)
tree24987ce1dcd12ea40bd802ceddf28952d02ec35b /drivers/hwtracing/coresight
parent96a7f644006ecc05eaaa1a5d09373d0ee63beb0a (diff)
coresight: tmc-etr: Relax collection of trace from sysfs mode
Since the ETR now uses mode specific buffers, we can reliably provide the trace data captured in sysfs mode, even when the ETR is operating in PERF mode. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing/coresight')
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc-etr.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 2d6f428176ff..bafd73e71c4c 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1168,19 +1168,17 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
goto out;
}
- /* Don't interfere if operated from Perf */
- if (drvdata->mode == CS_MODE_PERF) {
- ret = -EINVAL;
- goto out;
- }
-
- /* If sysfs_buf is NULL the trace data has been read already */
+ /*
+ * We can safely allow reads even if the ETR is operating in PERF mode,
+ * since the sysfs session is captured in mode specific data.
+ * If drvdata::sysfs_data is NULL the trace data has been read already.
+ */
if (!drvdata->sysfs_buf) {
ret = -EINVAL;
goto out;
}
- /* Disable the TMC if we are trying to read from a running session */
+ /* Disable the TMC if we are trying to read from a running session. */
if (drvdata->mode == CS_MODE_SYSFS)
tmc_etr_disable_hw(drvdata);