[PATCH v4 07/13] cpufreq: amd_pstate: map desired perf into pstate scope for powersave governor

Perry Yuan
2022-07-15T10:06:05Z

The patch will fix the invalid desired perf value for powersave
governor. This issue is found when testing on one AMD EPYC system, the
actual des_perf is smaller than the min_perf value, that is invalid
value. because the min_perf is the lowest_perf system can support in
idle state.

Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
---
drivers/cpufreq/amd-pstate.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 4b764870035e..ebc7c6d389be 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -268,6 +268,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
u64 prev = READ_ONCE(cpudata->cppc_req_cached);
u64 value = prev;

+ des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
value &= ~AMD_CPPC_MIN_PERF(~0L);
value |= AMD_CPPC_MIN_PERF(min_perf);

@@ -356,8 +357,6 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
if (max_perf < min_perf)
max_perf = min_perf;

- des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
-
amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true);
}

--
2.32.0