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@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 Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com
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