diff mbox series

[v7,04/13] cpufreq: amd-pstate: fix kernel hang issue while amd-pstate unregistering

Message ID 20221208111852.386731-5-perry.yuan@amd.com
State Superseded
Headers show
Series Implement AMD Pstate EPP Driver | expand

Commit Message

Perry Yuan Dec. 8, 2022, 11:18 a.m. UTC
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@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Huang Rui Dec. 9, 2022, 8:56 a.m. UTC | #1
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@amd.com>

Acked-by: Huang Rui <ray.huang@amd.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
>
diff mbox series

Patch

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)