| From foo@baz Sat Nov 10 11:24:34 PST 2018 |
| From: Suzuki K Poulose <suzuki.poulose@arm.com> |
| Date: Thu, 20 Sep 2018 13:17:46 -0600 |
| Subject: coresight: etb10: Fix handling of perf mode |
| |
| 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; |
