cpufreq/amd-pstate: Remove the defensive check for bios_min_perf

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Initialization of bios_min_perf (BIOS Requested CPU Min Freq.) only
succeeds when the driver init finds the CPPC_REQ MSRs to have all 0s
except for MIN_PERF bits.

A kexec puts the driver through the suspend path which, although resets
the min_perf back to bios_min_perf, keeps the rest of the CPPR_REQ
intact with the last value at the time of suspend.

The defensive check for bios_min_perf exists to prevent the min perf
from last CPPC_REQ being incorrectly considered as bios_min_perf when
a kexec switches from an older kernel running the version of driver
which is not aware of bios_min_perf to a newer one.

This scenario is extremely unlikely and Mario suggested it is better to
simplify the initialization rather than complicating the suspend resume
paths.

Drop the defensive check for bios_min_perf initialization and add a
debug message to dump the BIOS Requested Min Freq. to console leaving
enough breadcrumbs for debug if a situation so arises.

Suggested-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20260727072056.1248-3-kprateek.nayak@amd.com
Signed-off-by: Mario Limonciello <superm1@kernel.org>

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This commit is contained in:

K Prateek Nayak 2026-07-27 07:20:49 +00:00 • committed by Mario Limonciello

parent 5c3ecf36d2

commit 0e85027801

1 changed files with 8 additions and 11 deletions

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drivers/cpufreq/amd-pstate.c

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