Re: [PATCH 1/2] cpufreq: allow cpuinfo max to decrease when boost is disabled
From: Sibi Sankar
Date: Thu Aug 06 2026 - 06:16:30 EST
On 8/6/2026 2:58 PM, Dmitry Baryshkov wrote:
On Thu, Aug 06, 2026 at 10:12:29AM +0530, Sibi Sankar wrote:
From: Ananthu C V <ananthu.cv@xxxxxxxxxxxxxxxx>Why is this bad?
Commit 538b0188da46 ("cpufreq: ACPI: Set cpuinfo.max_freq directly
if max boost is known") guarded cpuinfo max updates to only allow
increases, preserving values set directly by drivers above the freq
table maximum. This prevents cpuinfo max from decreasing on boost
disable, leaving policy max pinned at the boost ceiling.
Copy pasting logs shared from the cover letter:
# cd /sys/devices/system/cpu/cpufreq/
# ls
boost policy0 policy12 policy6
# cat boost
0
# cat policy6/scaling_max_freq
4454400
# echo 1 > boost
# cat policy6/scaling_max_freq
4723200
# echo 0 > boost
# cat policy6/scaling_max_freq
4723200
Currently disabling boost after enabling it is a NOP,
scaling_max freq in this case would be pinned to turbo.
It will be reachable through various govenors. Also policy
specific boost flag is meaningless unless we have means to
reduce the scaling_max_freq.
Remove the guard so cpuinfo max is always derived from the frequency
table scan. Drivers that correctly flag boost entries are unaffected
since the scan already excludes them when boost is off.
Fixes: 538b0188da46 ("cpufreq: ACPI: Set cpuinfo.max_freq directly if max boost is known")
Signed-off-by: Ananthu C V <ananthu.cv@xxxxxxxxxxxxxxxx>
Signed-off-by: Sibi Sankar <sibi.sankar@xxxxxxxxxxxxxxxx>
---
drivers/cpufreq/freq_table.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)