[PATCH v2] coresight: tpdm: fix invalid MMIO access issue

[Jie Gan]

Create the csdev_access struct only when a valid MMIO resource is
available. In tpdm_probe(), base is uninitialized for static TPDM
instances that lack an MMIO resource, causing csdev_access to be
created with a garbage address.

So far there has no register access for static instance, but this
change helps mitigate potential risks in the future.

Fixes: 14ae052f7947 ("coresight: tpdm: add static tpdm support")
Reviewed-by: Leo Yan <leo.yan@xxxxxxx>
Signed-off-by: Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
---
Changes in v2:
- add more description in the commit message to clarify the change.
- Link to v1: https://lore.kernel.org/r/20260407-fix-potential-issue-in-tpdm-v1-1-42090d27c0a8@xxxxxxxxxxxxxxxx
---
 drivers/hwtracing/coresight/coresight-tpdm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 9b16f368a58b..eaf7210af648 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -1430,6 +1430,7 @@ static int tpdm_probe(struct device *dev, struct resource *res)
 		if (ret)
 			return ret;
 
+		desc.access = CSDEV_ACCESS_IOMEM(base);
 		if (tpdm_has_dsb_dataset(drvdata))
 			of_property_read_u32(drvdata->dev->of_node,
 					     "qcom,dsb-msrs-num", &drvdata->dsb_msr_num);
@@ -1452,7 +1453,6 @@ static int tpdm_probe(struct device *dev, struct resource *res)
 	desc.ops = &tpdm_cs_ops;
 	desc.pdata = dev->platform_data;
 	desc.dev = dev;
-	desc.access = CSDEV_ACCESS_IOMEM(base);
 	if (res)
 		desc.groups = tpdm_attr_grps;
 	else

---
base-commit: 816f193dd0d95246f208590924dd962b192def78
change-id: 20260407-fix-potential-issue-in-tpdm-b07b44416051

Best regards,
-- 
Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>