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-rw-r--r--drivers/hwtracing/coresight/coresight.c22
1 files changed, 15 insertions, 7 deletions
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index e571e4010dff..366c1d493af3 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -140,12 +140,14 @@ static int coresight_enable_sink(struct coresight_device *csdev, u32 mode)
{
int ret;
- if (!csdev->enable) {
- if (sink_ops(csdev)->enable) {
- ret = sink_ops(csdev)->enable(csdev, mode);
- if (ret)
- return ret;
- }
+ /*
+ * We need to make sure the "new" session is compatible with the
+ * existing "mode" of operation.
+ */
+ if (sink_ops(csdev)->enable) {
+ ret = sink_ops(csdev)->enable(csdev, mode);
+ if (ret)
+ return ret;
csdev->enable = true;
}
@@ -347,8 +349,14 @@ int coresight_enable_path(struct list_head *path, u32 mode)
switch (type) {
case CORESIGHT_DEV_TYPE_SINK:
ret = coresight_enable_sink(csdev, mode);
+ /*
+ * Sink is the first component turned on. If we
+ * failed to enable the sink, there are no components
+ * that need disabling. Disabling the path here
+ * would mean we could disrupt an existing session.
+ */
if (ret)
- goto err;
+ goto out;
break;
case CORESIGHT_DEV_TYPE_SOURCE:
/* sources are enabled from either sysFS or Perf */