diff options
| author | K Prateek Nayak <kprateek.nayak@amd.com> | 2026-07-27 07:20:49 +0000 |
|---|---|---|
| committer | Mario Limonciello <superm1@kernel.org> | 2026-07-27 19:46:50 -0500 |
| commit | 0e850278016ee7207b58f4e38fa5303ea6a751b4 (patch) | |
| tree | 33369b9587d41317d9c6891f39a3b67ae9f9cc29 /tools/perf/scripts | |
| parent | 5c3ecf36d2918facff40548ee6ae28eef0865266 (diff) | |
cpufreq/amd-pstate: Remove the defensive check for bios_min_perf
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>
Diffstat (limited to 'tools/perf/scripts')
0 files changed, 0 insertions, 0 deletions
