From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Yuho Choi <dbgh9129@gmail.com>, suzuki.poulose@arm.com
Cc: mike.leach@arm.com, james.clark@linaro.org, leo.yan@arm.com,
alexander.shishkin@linux.intel.com, coresight@lists.linaro.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1] coresight: Check runtime PM resume result
Date: Mon, 3 Aug 2026 10:32:59 +0530 [thread overview]
Message-ID: <43e0e681-dbd6-4f1a-9fe1-520dba58ffd9@arm.com> (raw)
In-Reply-To: <20260802232552.593435-1-dbgh9129@gmail.com>
On 03/08/26 4:55 AM, Yuho Choi wrote:
> coresight_get_ref() ignores the return value of pm_runtime_get_sync()
> and reports success even when runtime resume fails. A path is then built
> and the CoreSight device may be accessed while it remains powered off.
>
> Use pm_runtime_resume_and_get() so a failed resume is reported and its
> runtime PM usage reference is rolled back. Drop the module and device
> references acquired before the resume attempt when it fails.
>
> Fixes: 5da5325fa856 ("coresight: moving PM runtime operations to core framework")
> Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
> ---
Should 'Fixes:' be tagging the following commit - which had introduced
coresight_get_ref() unconditionally calling pm_runtime_get_sync() ?
32b0707a4182 ("coresight: Add try_get_module() in coresight_grab_device()")
> drivers/hwtracing/coresight/coresight-core.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 6d65c43d574f..77d05b360484 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -843,7 +843,11 @@ static bool coresight_get_ref(struct coresight_device *csdev)
> goto err_module;
>
> /* Make sure the device is powered on */
> - pm_runtime_get_sync(parent);
> + if (pm_runtime_resume_and_get(parent) < 0) {
> + module_put(drv->owner);
> + goto err_module;
> + }
> +
> return true;
>
> err_module:
prev parent reply other threads:[~2026-08-03 5:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-02 23:25 [PATCH v1] coresight: Check runtime PM resume result Yuho Choi
2026-08-03 5:02 ` Anshuman Khandual [this message]
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