| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 095/222] coresight: etb10: Fix handling of perf mode | Date | Sun, 11 Nov 2018 14:23:12 -0800 |
| |
4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Suzuki K Poulose <suzuki.poulose@arm.com>
[ 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> --- drivers/hwtracing/coresight/coresight-etb10.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -155,6 +155,10 @@ static int etb_enable(struct coresight_d 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;
|