diff mbox series

[11/44] coresight: etb10: Fix handling of perf mode

Message ID 1537471099-19781-12-git-send-email-mathieu.poirier@linaro.org
State New
Headers show
Series coresight: next v4.19-rc4 | expand

Commit Message

Mathieu Poirier Sept. 20, 2018, 7:17 p.m. UTC 
From: Suzuki K Poulose <suzuki.poulose@arm.com>


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>

---
 drivers/hwtracing/coresight/coresight-etb10.c | 4 ++++
 1 file changed, 4 insertions(+)

-- 
2.7.4
diff mbox series

Patch

diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 306119eaf16a..0dad8626bcfb 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -147,6 +147,10 @@  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;