From: Perry Yuan <Perry.Yuan@amd.com>
To: <rafael.j.wysocki@intel.com>, <ray.huang@amd.com>,
<viresh.kumar@linaro.org>
Cc: <Deepak.Sharma@amd.com>, <Mario.Limonciello@amd.com>,
<Nathan.Fontenot@amd.com>, <Alexander.Deucher@amd.com>,
<Jinzhou.Su@amd.com>, <Shimmer.Huang@amd.com>,
<Xiaojian.Du@amd.com>, <Li.Meng@amd.com>,
<linux-pm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
Perry Yuan <Perry.Yuan@amd.com>
Subject: [PATCH] cpufreq: amd_pstate: Fix initial highest_perf value
Date: Mon, 15 Aug 2022 00:44:21 +0800 [thread overview]
Message-ID: <20220814164421.330891-1-Perry.Yuan@amd.com> (raw)
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..f778ab37e436 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.nominal_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
next reply other threads:[~2022-08-14 16:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-14 16:44 Perry Yuan [this message]
2022-08-25 11:58 ` [PATCH] cpufreq: amd_pstate: Fix initial highest_perf value Rafael J. Wysocki
2022-08-25 12:34 ` Yuan, Perry
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