[PATCH 5.8 282/633] coresight: cti: Fix bug clearing sysfs links on callback

From: Greg Kroah-Hartman
Date: Tue Oct 27 2020 - 11:07:22 EST


From: Mike Leach <mike.leach@xxxxxxxxxx>

[ Upstream commit cab280bf3533c72f95ebdb65ce534b5cdc4729dc ]

During module unload, a coresight driver module will call back into
the CTI driver to remove any links between the two devices.

The current code has 2 issues:-
1) in the CTI driver the matching code is matching to the wrong device
so misses all the links.
2) The callback is called too late in the unload process resulting in a
crash.

This fixes both the issues.

Fixes: 177af8285b59 ("coresight: cti: Enable CTI associated with devices")
Reported-by: Tingwei Zhang <tingwei@xxxxxxxxxxxxxx>
Acked-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx>
Signed-off-by: Tingwei Zhang <tingwei@xxxxxxxxxxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200928163513.70169-19-mathieu.poirier@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/hwtracing/coresight/coresight-cti.c | 2 +-
drivers/hwtracing/coresight/coresight.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
index 92aa535f9e134..167fbc2e7033f 100644
--- a/drivers/hwtracing/coresight/coresight-cti.c
+++ b/drivers/hwtracing/coresight/coresight-cti.c
@@ -592,7 +592,7 @@ void cti_remove_assoc_from_csdev(struct coresight_device *csdev)
ctidrv = csdev_to_cti_drvdata(csdev->ect_dev);
ctidev = &ctidrv->ctidev;
list_for_each_entry(tc, &ctidev->trig_cons, node) {
- if (tc->con_dev == csdev->ect_dev) {
+ if (tc->con_dev == csdev) {
cti_remove_sysfs_link(ctidrv, tc);
tc->con_dev = NULL;
break;
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index f3efbb3b2b4d1..cf03af09c6ced 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -1023,7 +1023,6 @@ static void coresight_device_release(struct device *dev)
{
struct coresight_device *csdev = to_coresight_device(dev);

- cti_remove_assoc_from_csdev(csdev);
fwnode_handle_put(csdev->dev.fwnode);
kfree(csdev->refcnt);
kfree(csdev);
@@ -1357,6 +1356,7 @@ void coresight_unregister(struct coresight_device *csdev)
{
etm_perf_del_symlink_sink(csdev);
/* Remove references of that device in the topology */
+ cti_remove_assoc_from_csdev(csdev);
coresight_remove_conns(csdev);
coresight_release_platform_data(csdev, csdev->pdata);
device_unregister(&csdev->dev);
--
2.25.1