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[PATCH v2] cpufreq: amd_pstate: Fix initial highest_perf value

Perry Yuan posted 1 patch 3 years, 7 months ago
There is a newer version of this series
drivers/cpufreq/amd-pstate.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
[PATCH v2] cpufreq: amd_pstate: Fix initial highest_perf value
Posted by Perry Yuan 3 years, 7 months ago 
To avoid some new AMD processors use wrong highest perf when amd pstate
driver loaded, this fix will query the highest perf from MSR register
MSR_AMD_CPPC_CAP1 and cppc_acpi interface firstly, then compare with the
highest perf value got by calling amd_get_highest_perf() function.

The lower value will be the correct highest perf we need to use.
Otherwise the CPU max MHz will be incorrect if the
amd_get_highest_perf() did not cover the new process family and model ID.

Like this lscpu info, the max frequency is incorrect.

Vendor ID:               AuthenticAMD
    Socket(s):           1
    Stepping:            2
    CPU max MHz:         5410.0000
    CPU min MHz:         400.0000
    BogoMIPS:            5600.54

Fixes: 3743d55b289c2 (x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations)
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 9f4375f7ab46..30fbd30c0949 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -354,6 +354,7 @@ static inline int amd_pstate_enable(bool enable)
 static int pstate_init_perf(struct amd_cpudata *cpudata)
 {
 	u64 cap1;
+	u32 highest_perf;
 
 	int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
 				     &cap1);
@@ -365,7 +366,11 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)
 	 *
 	 * CPPC entry doesn't indicate the highest performance in some ASICs.
 	 */
-	WRITE_ONCE(cpudata->highest_perf, amd_get_highest_perf());
+	highest_perf = amd_get_highest_perf();
+	if (highest_perf > AMD_CPPC_HIGHEST_PERF(cap1))
+		highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
+
+	WRITE_ONCE(cpudata->highest_perf, highest_perf);
 
 	WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1));
 	WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1));
@@ -377,12 +382,17 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)
 static int cppc_init_perf(struct amd_cpudata *cpudata)
 {
 	struct cppc_perf_caps cppc_perf;
+	u32 highest_perf;
 
 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
 	if (ret)
 		return ret;
 
-	WRITE_ONCE(cpudata->highest_perf, amd_get_highest_perf());
+	highest_perf = amd_get_highest_perf();
+	if (highest_perf > cppc_perf.highest_perf)
+		highest_perf = cppc_perf.highest_perf;
+
+	WRITE_ONCE(cpudata->highest_perf, highest_perf);
 
 	WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf);
 	WRITE_ONCE(cpudata->lowest_nonlinear_perf,
-- 
2.34.1
Re: [PATCH v2] cpufreq: amd_pstate: Fix initial highest_perf value
Posted by Huang Rui 3 years, 7 months ago 
On Mon, Aug 29, 2022 at 01:59:01PM +0800, Yuan, Perry wrote:
> To avoid some new AMD processors use wrong highest perf when amd pstate
> driver loaded, this fix will query the highest perf from MSR register
> MSR_AMD_CPPC_CAP1 and cppc_acpi interface firstly, then compare with the
> highest perf value got by calling amd_get_highest_perf() function.
> 
> The lower value will be the correct highest perf we need to use.
> Otherwise the CPU max MHz will be incorrect if the
> amd_get_highest_perf() did not cover the new process family and model ID.
> 
> Like this lscpu info, the max frequency is incorrect.
> 
> Vendor ID:               AuthenticAMD
>     Socket(s):           1
>     Stepping:            2
>     CPU max MHz:         5410.0000
>     CPU min MHz:         400.0000
>     BogoMIPS:            5600.54
> 
> Fixes: 3743d55b289c2 (x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations)
> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>

Acked-by: Huang Rui <ray.huang@amd.com>

> ---
>  drivers/cpufreq/amd-pstate.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 9f4375f7ab46..30fbd30c0949 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -354,6 +354,7 @@ static inline int amd_pstate_enable(bool enable)
>  static int pstate_init_perf(struct amd_cpudata *cpudata)
>  {
>  	u64 cap1;
> +	u32 highest_perf;
>  
>  	int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
>  				     &cap1);
> @@ -365,7 +366,11 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)
>  	 *
>  	 * CPPC entry doesn't indicate the highest performance in some ASICs.
>  	 */
> -	WRITE_ONCE(cpudata->highest_perf, amd_get_highest_perf());
> +	highest_perf = amd_get_highest_perf();
> +	if (highest_perf > AMD_CPPC_HIGHEST_PERF(cap1))
> +		highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
> +
> +	WRITE_ONCE(cpudata->highest_perf, highest_perf);
>  
>  	WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1));
>  	WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1));
> @@ -377,12 +382,17 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)
>  static int cppc_init_perf(struct amd_cpudata *cpudata)
>  {
>  	struct cppc_perf_caps cppc_perf;
> +	u32 highest_perf;
>  
>  	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
>  	if (ret)
>  		return ret;
>  
> -	WRITE_ONCE(cpudata->highest_perf, amd_get_highest_perf());
> +	highest_perf = amd_get_highest_perf();
> +	if (highest_perf > cppc_perf.highest_perf)
> +		highest_perf = cppc_perf.highest_perf;
> +
> +	WRITE_ONCE(cpudata->highest_perf, highest_perf);
>  
>  	WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf);
>  	WRITE_ONCE(cpudata->lowest_nonlinear_perf,
> -- 
> 2.34.1
>
Re: [PATCH v2] cpufreq: amd_pstate: Fix initial highest_perf value
Posted by Huang Rui 3 years, 7 months ago 
On Mon, Aug 29, 2022 at 01:59:01PM +0800, Yuan, Perry wrote:
> To avoid some new AMD processors use wrong highest perf when amd pstate
> driver loaded, this fix will query the highest perf from MSR register
> MSR_AMD_CPPC_CAP1 and cppc_acpi interface firstly, then compare with the
> highest perf value got by calling amd_get_highest_perf() function.
> 
> The lower value will be the correct highest perf we need to use.
> Otherwise the CPU max MHz will be incorrect if the
> amd_get_highest_perf() did not cover the new process family and model ID.
> 
> Like this lscpu info, the max frequency is incorrect.
> 
> Vendor ID:               AuthenticAMD
>     Socket(s):           1
>     Stepping:            2
>     CPU max MHz:         5410.0000
>     CPU min MHz:         400.0000
>     BogoMIPS:            5600.54
> 
> Fixes: 3743d55b289c2 (x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations)
> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>

Acked-by: Huang Rui <ray.huang@amd.com>

> ---
>  drivers/cpufreq/amd-pstate.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 9f4375f7ab46..30fbd30c0949 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -354,6 +354,7 @@ static inline int amd_pstate_enable(bool enable)
>  static int pstate_init_perf(struct amd_cpudata *cpudata)
>  {
>  	u64 cap1;
> +	u32 highest_perf;
>  
>  	int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
>  				     &cap1);
> @@ -365,7 +366,11 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)
>  	 *
>  	 * CPPC entry doesn't indicate the highest performance in some ASICs.
>  	 */
> -	WRITE_ONCE(cpudata->highest_perf, amd_get_highest_perf());
> +	highest_perf = amd_get_highest_perf();
> +	if (highest_perf > AMD_CPPC_HIGHEST_PERF(cap1))
> +		highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
> +
> +	WRITE_ONCE(cpudata->highest_perf, highest_perf);
>  
>  	WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1));
>  	WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1));
> @@ -377,12 +382,17 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)
>  static int cppc_init_perf(struct amd_cpudata *cpudata)
>  {
>  	struct cppc_perf_caps cppc_perf;
> +	u32 highest_perf;
>  
>  	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
>  	if (ret)
>  		return ret;
>  
> -	WRITE_ONCE(cpudata->highest_perf, amd_get_highest_perf());
> +	highest_perf = amd_get_highest_perf();
> +	if (highest_perf > cppc_perf.highest_perf)
> +		highest_perf = cppc_perf.highest_perf;
> +
> +	WRITE_ONCE(cpudata->highest_perf, highest_perf);
>  
>  	WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf);
>  	WRITE_ONCE(cpudata->lowest_nonlinear_perf,
> -- 
> 2.34.1
>

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