[PATCH AUTOSEL 4.9 18/34] coresight: Handle errors in finding input/output ports

Sasha Levin
2018-09-15T01:40:01Z

From: Suzuki K Poulose <suzuki.poulose@arm.com>

[ Upstream commit fe470f5f7f684ed15bc49b6183a64237547910ff ]

If we fail to find the input / output port for a LINK component
while enabling a path, we should fail gracefully rather than
assuming port "0".

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 <alexander.levin@microsoft.com>
---
drivers/hwtracing/coresight/coresight.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 4383324ec01c..398e44a9ec45 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -107,7 +107,7 @@ static int coresight_find_link_inport(struct coresight_device *csdev,
dev_err(&csdev->dev, "couldn't find inport, parent: %s, child: %s\n",
dev_name(&parent->dev), dev_name(&csdev->dev));

- return 0;
+ return -ENODEV;
}

static int coresight_find_link_outport(struct coresight_device *csdev,
@@ -125,7 +125,7 @@ static int coresight_find_link_outport(struct coresight_device *csdev,
dev_err(&csdev->dev, "couldn't find outport, parent: %s, child: %s\n",
dev_name(&csdev->dev), dev_name(&child->dev));

- return 0;
+ return -ENODEV;
}

static int coresight_enable_sink(struct coresight_device *csdev, u32 mode)
@@ -178,6 +178,9 @@ static int coresight_enable_link(struct coresight_device *csdev,
else
refport = 0;

+ if (refport < 0)
+ return refport;
+
if (atomic_inc_return(&csdev->refcnt[refport]) == 1) {
if (link_ops(csdev)->enable) {
ret = link_ops(csdev)->enable(csdev, inport, outport);
--
2.17.1