On 23/01/2024 05:45, Anshuman Khandual wrote:
There is an unbalanced pm_runtime_enable() in etm4_probe_platform_dev()
when etm4_probe() fails. This problem can be observed via the coresight
etm4 module's (load -> unload -> load) sequence when etm4_probe() fails
in etm4_probe_platform_dev().
[ 63.379943] coresight-etm4x 7040000.etm: Unbalanced pm_runtime_enable!
[ 63.393630] coresight-etm4x 7140000.etm: Unbalanced pm_runtime_enable!
[ 63.407455] coresight-etm4x 7240000.etm: Unbalanced pm_runtime_enable!
[ 63.420983] coresight-etm4x 7340000.etm: Unbalanced pm_runtime_enable!
[ 63.420999] coresight-etm4x 7440000.etm: Unbalanced pm_runtime_enable!
[ 63.441209] coresight-etm4x 7540000.etm: Unbalanced pm_runtime_enable!
[ 63.454689] coresight-etm4x 7640000.etm: Unbalanced pm_runtime_enable!
[ 63.474982] coresight-etm4x 7740000.etm: Unbalanced pm_runtime_enable!
This fixes the above problem - with an explicit pm_runtime_disable() call
when etm4_probe() fails during etm4_probe_platform_dev().
Fixes: 5214b563588e ("coresight: etm4x: Add support for sysreg only devices"
Cc: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
Cc: Hanjun Guo <guohanjun@xxxxxxxxxx>
Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: Mike Leach <mike.leach@xxxxxxxxxx>
Cc: James Clark <james.clark@xxxxxxx>
Cc: Leo Yan <leo.yan@xxxxxxxxxx>
Cc: linux-acpi@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: coresight@xxxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
Changes in V4:
- New patch in the series
drivers/hwtracing/coresight/coresight-etm4x-core.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index ce1995a2827f..7c693b45ac05 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -2217,6 +2217,9 @@ static int etm4_probe_platform_dev(struct platform_device *pdev)
ret = etm4_probe(&pdev->dev);
pm_runtime_put(&pdev->dev);
+ if (ret)
+ pm_runtime_disable(&pdev->dev);
+
return ret;
}
Looks good to me. I have glanced through the other platform device
driver code in coresight subsystem and they all seem to be safe, except
for Ultrasoc-smb, which doesn't do any power managment. It may be,
because it is only supported on an ACPI system.
Suzuki
