Hi stable team,
Please backport the mainline commit
bf202e654bfa ("cpufreq: amd-pstate: fix the highest frequency issue which limits performance")
to the 6.9 stable series.
It fixes a performance regression on AMD Phoenix platforms.
It was meant to get into the 6.9 release or the stable branch shortly
after, but apparently that didn't happen.
On 2024-05-08 13:47:03+0000, Perry Yuan wrote:
> To address the performance drop issue, an optimization has been
> implemented. The incorrect highest performance value previously set by the
> low-level power firmware for AMD CPUs with Family ID 0x19 and Model ID
> ranging from 0x70 to 0x7F series has been identified as the cause.
>
> To resolve this, a check has been implemented to accurately determine the
> CPU family and model ID. The correct highest performance value is now set
> and the performance drop caused by the incorrect highest performance value
> are eliminated.
>
> Before the fix, the highest frequency was set to 4200MHz, now it is set
> to 4971MHz which is correct.
>
> CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ MINMHZ MHZ
> 0 0 0 0 0:0:0:0 yes 4971.0000 400.0000 400.0000
> 1 0 0 0 0:0:0:0 yes 4971.0000 400.0000 400.0000
> 2 0 0 1 1:1:1:0 yes 4971.0000 400.0000 4865.8140
> 3 0 0 1 1:1:1:0 yes 4971.0000 400.0000 400.0000
>
> v1->v2:
> * add test by flag from Gaha Bana
>
> Fixes: f3a052391822 ("cpufreq: amd-pstate: Enable amd-pstate preferred core support")
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218759
> Signed-off-by: Perry Yuan <perry.yuan@xxxxxxx>
> Co-developed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> Tested-by: Gaha Bana <gahabana@xxxxxxxxx>
> ---
> drivers/cpufreq/amd-pstate.c | 22 +++++++++++++++++++---
> 1 file changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 2db095867d03..6a342b0c0140 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -50,7 +50,8 @@
>
> #define AMD_PSTATE_TRANSITION_LATENCY 20000
> #define AMD_PSTATE_TRANSITION_DELAY 1000
> -#define AMD_PSTATE_PREFCORE_THRESHOLD 166
> +#define CPPC_HIGHEST_PERF_PERFORMANCE 196
> +#define CPPC_HIGHEST_PERF_DEFAULT 166
>
> /*
> * TODO: We need more time to fine tune processors with shared memory solution
> @@ -326,6 +327,21 @@ static inline int amd_pstate_enable(bool enable)
> return static_call(amd_pstate_enable)(enable);
> }
>
> +static u32 amd_pstate_highest_perf_set(struct amd_cpudata *cpudata)
> +{
> + struct cpuinfo_x86 *c = &cpu_data(0);
> +
> + /*
> + * For AMD CPUs with Family ID 19H and Model ID range 0x70 to 0x7f,
> + * the highest performance level is set to 196.
> + * https://bugzilla.kernel.org/show_bug.cgi?id=218759
> + */
> + if (c->x86 == 0x19 && (c->x86_model >= 0x70 && c->x86_model <= 0x7f))
> + return CPPC_HIGHEST_PERF_PERFORMANCE;
> +
> + return CPPC_HIGHEST_PERF_DEFAULT;
> +}
> +
> static int pstate_init_perf(struct amd_cpudata *cpudata)
> {
> u64 cap1;
> @@ -342,7 +358,7 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)
> * the default max perf.
> */
> if (cpudata->hw_prefcore)
> - highest_perf = AMD_PSTATE_PREFCORE_THRESHOLD;
> + highest_perf = amd_pstate_highest_perf_set(cpudata);
> else
> highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
>
> @@ -366,7 +382,7 @@ static int cppc_init_perf(struct amd_cpudata *cpudata)
> return ret;
>
> if (cpudata->hw_prefcore)
> - highest_perf = AMD_PSTATE_PREFCORE_THRESHOLD;
> + highest_perf = amd_pstate_highest_perf_set(cpudata);
> else
> highest_perf = cppc_perf.highest_perf;
>
> --
> 2.34.1
>
