[PATCH] coresight: Only register perf symlink for sinks with alloc_buffer

[Yuanfang Zhang]

Ensure that etm_perf_add_symlink_sink() is only called for devices
that implement the alloc_buffer operation. This prevents invalid
symlink creation for dummy sinks that do not implement alloc_buffer.

Without this check, perf may attempt to use a dummy sink that lacks
alloc_buffer operationsu to initialise perf's ring buffer, leading
to runtime failures.

Fixes: 9d3ba0b6c0569 ("Coresight: Add coresight dummy driver")
Signed-off-by: Yuanfang Zhang <quic_yuanfang at quicinc.com>
---
 drivers/hwtracing/coresight/coresight-core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index fa758cc21827552a5c97b6bdd05d22dec4994b22..fddf04c5ee46eb4d559416296f7e85ce6c5689fa 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1374,8 +1374,9 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
 		goto out_unlock;
 	}
 
-	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
-	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+	if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
+	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
+	    sink_ops(csdev)->alloc_buffer) {
 		ret = etm_perf_add_symlink_sink(csdev);
 
 		if (ret) {

---
base-commit: 408c97c4a5e0b634dcd15bf8b8808b382e888164
change-id: 20250630-etm_perf_sink-ee0fcffc6820

Best regards,
-- 
Yuanfang Zhang <quic_yuanfang at quicinc.com>