diff mbox series

[v5,19/19] cpufreq/amd-pstate: Drop actions in amd_pstate_epp_cpu_offline()

Message ID 20250226074934.1667721-20-superm1@kernel.org
State New
Headers show
Series amd-pstate cleanups | expand

Commit Message

Mario Limonciello Feb. 26, 2025, 7:49 a.m. UTC 
From: Mario Limonciello <mario.limonciello@amd.com>

When the CPU goes offline there is no need to change the CPPC request
because the CPU will go into the deepest C-state it supports already.

Actually changing the CPPC request when it goes offline messes up the
cached values and can lead to the wrong values being restored when
it comes back.

Instead drop the actions and if the CPU comes back online let
amd_pstate_epp_set_policy() restore it to expected values.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v5:
 * Reword commit message
 * Add tag
---
 drivers/cpufreq/amd-pstate.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

Comments

Gautham R. Shenoy March 4, 2025, 5:11 a.m. UTC | #1 
On Wed, Feb 26, 2025 at 01:49:34AM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> When the CPU goes offline there is no need to change the CPPC request
> because the CPU will go into the deepest C-state it supports already.
> 
> Actually changing the CPPC request when it goes offline messes up the
> cached values and can lead to the wrong values being restored when
> it comes back.
> 
> Instead drop the actions and if the CPU comes back online let
> amd_pstate_epp_set_policy() restore it to expected values.
> 
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v5:
>  * Reword commit message
>  * Add tag
> ---
>  drivers/cpufreq/amd-pstate.c | 9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 24a1f9e129b61..4a364ae9b56a1 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1580,14 +1580,7 @@ static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
>  
>  static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
>  {
> -	struct amd_cpudata *cpudata = policy->driver_data;
> -	union perf_cached perf = READ_ONCE(cpudata->perf);
> -
> -	if (cpudata->suspended)
> -		return 0;
> -
> -	return amd_pstate_update_perf(policy, perf.lowest_perf, 0, perf.lowest_perf,
> -				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
> +	return 0;

LGTM

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
diff mbox series

Patch

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 24a1f9e129b61..4a364ae9b56a1 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1580,14 +1580,7 @@  static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
 
 static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 {
-	struct amd_cpudata *cpudata = policy->driver_data;
-	union perf_cached perf = READ_ONCE(cpudata->perf);
-
-	if (cpudata->suspended)
-		return 0;
-
-	return amd_pstate_update_perf(policy, perf.lowest_perf, 0, perf.lowest_perf,
-				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
+	return 0;
 }
 
 static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)