[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <Y5L4RWjrfV65/eKD@amd.com>
Date: Fri, 9 Dec 2022 16:56:37 +0800
From: Huang Rui <ray.huang@....com>
To: "Yuan, Perry" <Perry.Yuan@....com>
Cc: "rafael.j.wysocki@...el.com" <rafael.j.wysocki@...el.com>,
"Limonciello, Mario" <Mario.Limonciello@....com>,
"viresh.kumar@...aro.org" <viresh.kumar@...aro.org>,
"Sharma, Deepak" <Deepak.Sharma@....com>,
"Fontenot, Nathan" <Nathan.Fontenot@....com>,
"Deucher, Alexander" <Alexander.Deucher@....com>,
"Huang, Shimmer" <Shimmer.Huang@....com>,
"Du, Xiaojian" <Xiaojian.Du@....com>,
"Meng, Li (Jassmine)" <Li.Meng@....com>,
"Karny, Wyes" <Wyes.Karny@....com>,
"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v7 04/13] cpufreq: amd-pstate: fix kernel hang issue
while amd-pstate unregistering
On Thu, Dec 08, 2022 at 07:18:43PM +0800, Yuan, Perry wrote:
> In the amd_pstate_adjust_perf(), there is one cpufreq_cpu_get() call to
> increase increments the kobject reference count of policy and make it as
> busy. Therefore, a corresponding call to cpufreq_cpu_put() is needed to
> decrement the kobject reference count back, it will resolve the kernel
> hang issue when unregistering the amd-pstate driver and register the
> `amd_pstate_epp` driver instance.
>
> Signed-off-by: Perry Yuan <perry.yuan@....com>
Acked-by: Huang Rui <ray.huang@....com>
> ---
> drivers/cpufreq/amd-pstate.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 204e39006dda..c17bd845f5fc 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -307,6 +307,7 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
> max_perf = min_perf;
>
> amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true);
> + cpufreq_cpu_put(policy);
> }
>
> static int amd_get_min_freq(struct amd_cpudata *cpudata)
> --
> 2.34.1
>
Powered by blists - more mailing lists