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authorSuzuki K Poulose <suzuki.poulose@arm.com>2018-09-20 22:17:46 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-13 22:14:59 +0300
commit0d20b616732e103070f2ffcd061ec0812754808a (patch)
tree1143ae6f0488ab55b088ad7b409c9f34b422c7d7 /drivers/hwtracing
parent8cc76433d8c9dd666c19b1aaefd5c55a31115f89 (diff)
downloadlinux-0d20b616732e103070f2ffcd061ec0812754808a.tar.xz
coresight: etb10: Fix handling of perf mode
[ Upstream commit 987d1e8dcd370d96029a3d76a0031b043c4a69ae ] If the ETB is already enabled in sysfs mode, the ETB reports success even if a perf mode is requested. Fix this by checking the requested 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> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/coresight/coresight-etb10.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 56ecd7aff5eb..d14a9cb7959a 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -155,6 +155,10 @@ static int etb_enable(struct coresight_device *csdev, u32 mode)
if (val == CS_MODE_PERF)
return -EBUSY;
+ /* Don't let perf disturb sysFS sessions */
+ if (val == CS_MODE_SYSFS && mode == CS_MODE_PERF)
+ return -EBUSY;
+
/* Nothing to do, the tracer is already enabled. */
if (val == CS_MODE_SYSFS)
goto out;