coresight: etm4x: Fix unbalanced pm_runtime_enable()

[ Upstream commit caa41c47dab7e1054f587e592ab21296e3a6781c ]

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().

Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: James Clark <james.clark@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: linux-acpi@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: coresight@lists.linaro.org
Fixes: 5214b563588e ("coresight: etm4x: Add support for sysreg only devices")
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20240314055843.2625883-2-anshuman.khandual@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 26d0d4485ae99f05cdeb523833420434ea8ed809..3f5e9400222e7cf8cbd0bef731f5cd9636fffaab 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -2022,6 +2022,9 @@ static int etm4_probe_platform_dev(struct platform_device *pdev)
        ret = etm4_probe(&pdev->dev, NULL, 0);
 
        pm_runtime_put(&pdev->dev);
+       if (ret)
+               pm_runtime_disable(&pdev->dev);
+
        return ret;
 }