diff mbox series

cpufreq: amd-pstate: fix kernel hang issue while amd-pstate unregistering

Message ID 20230106054856.37403-1-perry.yuan@amd.com
State New
Headers
Series cpufreq: amd-pstate: fix kernel hang issue while amd-pstate unregistering |

Commit Message

Yuan, Perry Jan. 6, 2023, 5:48 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.

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>
Cc: stable@vger.kernel.org
---
 drivers/cpufreq/amd-pstate.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Wyes Karny Jan. 9, 2023, 3:38 p.m. UTC | #1 
On 1/6/2023 11:18 AM, Perry Yuan 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
> ---
>  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)
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)