diff options
| author | Dhananjay Ugwekar <dhananjay.ugwekar@amd.com> | 2025-02-22 03:32:22 +0000 |
|---|---|---|
| committer | Mario Limonciello <mario.limonciello@amd.com> | 2025-03-06 13:01:17 -0600 |
| commit | a1d1d8fb653532638cfb3ee0b7e67ebd5327a3d6 (patch) | |
| tree | 342a54e5dc9b109cd3d0d44261341a9f450972cd | |
| parent | 3e93edc58a63cf816e6dc853da8e9b0201bd0298 (diff) | |
cpufreq/amd-pstate: Fix the clamping of perf values
The clamping in freq_to_perf() is broken right now, as we first typecast
(read wraparound) the overflowing value into a u8 and then clamp it down.
So, use a u32 to store the >255 value in certain edge cases and then clamp
it down into a u8.
Also, use a "explicit typecast + clamp" instead of just a "clamp_t" as the
latter typecasts first and then clamps between the limits, which defeats
our purpose.
Fixes: 620136ced35a ("cpufreq/amd-pstate: Modularize perf<->freq conversion")
Signed-off-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20250222033221.554976-1-dhananjay.ugwekar@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
| -rw-r--r-- | drivers/cpufreq/amd-pstate.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 08ae48076812..56930424c9fa 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -144,10 +144,10 @@ static struct quirk_entry quirk_amd_7k62 = { static inline u8 freq_to_perf(struct amd_cpudata *cpudata, unsigned int freq_val) { - u8 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * cpudata->nominal_perf, + u32 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * cpudata->nominal_perf, cpudata->nominal_freq); - return clamp_t(u8, perf_val, cpudata->lowest_perf, cpudata->highest_perf); + return (u8)clamp(perf_val, cpudata->lowest_perf, cpudata->highest_perf); } static inline u32 perf_to_freq(struct amd_cpudata *cpudata, u8 perf_val) |