36 lines
1.5 KiB
Diff
36 lines
1.5 KiB
Diff
From f09ef5b8aacd5b16ac1ea93103b41a7e88b174ed Mon Sep 17 00:00:00 2001
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From: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
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Date: Sat, 22 Feb 2025 03:32:22 +0000
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Subject: cpufreq/amd-pstate: Fix the clamping of perf values
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The clamping in freq_to_perf() is broken right now, as we first typecast
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(read wraparound) the overflowing value into a u8 and then clamp it down.
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So, use a u32 to store the >255 value in certain edge cases and then clamp
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it down into a u8.
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Also, use a "explicit typecast + clamp" instead of just a "clamp_t" as the
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latter typecasts first and then clamps between the limits, which defeats
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our purpose.
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Fixes: 305621eb6a8b ("cpufreq/amd-pstate: Modularize perf<->freq conversion")
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Signed-off-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
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---
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drivers/cpufreq/amd-pstate.c | 4 ++--
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1 file changed, 2 insertions(+), 2 deletions(-)
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--- a/drivers/cpufreq/amd-pstate.c
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+++ b/drivers/cpufreq/amd-pstate.c
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@@ -144,10 +144,10 @@ static struct quirk_entry quirk_amd_7k62
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static inline u8 freq_to_perf(struct amd_cpudata *cpudata, unsigned int freq_val)
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{
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- u8 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * cpudata->nominal_perf,
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+ u32 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * cpudata->nominal_perf,
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cpudata->nominal_freq);
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- return clamp_t(u8, perf_val, cpudata->lowest_perf, cpudata->highest_perf);
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+ return (u8)clamp(perf_val, cpudata->lowest_perf, cpudata->highest_perf);
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}
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static inline u32 perf_to_freq(struct amd_cpudata *cpudata, u8 perf_val)
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