From: Mao Jinlong <quic_jinlmao@xxxxxxxxxxx>
[ Upstream commit eff674a9b86a6ffdd10c3af3863545acf7f1ce4f ]
In commit 6746eae4bbad ("coresight: cti: Fix hang in cti_disable_hw()")
PM runtime calls are removed from cti_enable_hw/cti_disable_hw. When
enabling CTI by writing enable sysfs node, clock for accessing CTI
register won't be enabled. Device will crash due to register access
issue. Add PM runtime call in enable_store to fix this issue.
Fixes: 6746eae4bbad ("coresight: cti: Fix hang in cti_disable_hw()")
Signed-off-by: Mao Jinlong <quic_jinlmao@xxxxxxxxxxx>
[Change to only call pm_runtime_put if a disable happened]
Tested-by: Jinlong Mao <quic_jinlmao@xxxxxxxxxxx>
Signed-off-by: James Clark <james.clark@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Link: https://lore.kernel.org/r/20230110110736.2709917-3-james.clark@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/hwtracing/coresight/coresight-cti-sysfs.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
index 6d59c815ecf5e..71e7a8266bb32 100644
--- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
@@ -108,10 +108,19 @@ static ssize_t enable_store(struct device *dev,
if (ret)
return ret;
- if (val)
+ if (val) {
+ ret = pm_runtime_resume_and_get(dev->parent);
+ if (ret)
+ return ret;
ret = cti_enable(drvdata->csdev);
- else
+ if (ret)
+ pm_runtime_put(dev->parent);
+ } else {
ret = cti_disable(drvdata->csdev);
+ if (!ret)
+ pm_runtime_put(dev->parent);
+ }
+
if (ret)
return ret;
return size;
--
2.39.2
