Messages in this thread | | | From | "Yuan, Perry" <> | Subject | RE: [PATCH v2] cpufreq: amd-pstate: fix kernel hang issue while amd-pstate unregistering | Date | Tue, 10 Jan 2023 15:02:52 +0000 |
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[AMD Official Use Only - General]
Hi Rafael:
> -----Original Message----- > From: Rafael J. Wysocki <rafael@kernel.org> > Sent: Tuesday, January 10, 2023 8:58 PM > To: Yuan, Perry <Perry.Yuan@amd.com> > Cc: rafael.j.wysocki@intel.com; Limonciello, Mario > <Mario.Limonciello@amd.com>; Huang, Ray <Ray.Huang@amd.com>; > viresh.kumar@linaro.org; Sharma, Deepak <Deepak.Sharma@amd.com>; > Fontenot, Nathan <Nathan.Fontenot@amd.com>; Deucher, Alexander > <Alexander.Deucher@amd.com>; Huang, Shimmer > <Shimmer.Huang@amd.com>; Du, Xiaojian <Xiaojian.Du@amd.com>; Meng, > Li (Jassmine) <Li.Meng@amd.com>; Karny, Wyes <Wyes.Karny@amd.com>; > linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH v2] cpufreq: amd-pstate: fix kernel hang issue while > amd-pstate unregistering > > On Tue, Jan 10, 2023 at 1:50 PM Perry Yuan <perry.yuan@amd.com> 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. > > > > Acked-by: Huang Rui <ray.huang@amd.com> > > Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> > > Signed-off-by: Perry Yuan <perry.yuan@amd.com> > > Tested-by: Wyes Karny <wyes.karny@amd.com> > > Cc: stable@vger.kernel.org > > Can you provide a Fixes tag, please?
Sure, let me add the Fixes tag in v3
> > Also, what's the difference between this and the previous version?
Just add the "Tested-by: Wyes Karny <wyes.karny@amd.com>" in v2.
> > > --- > > 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 > >
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