cpufreq/amd-pstate: Fix EPP return type and handle errors during initialization

Browse source

Currently, the EPP getter helper functions (msr_get_epp, shmem_get_epp, and
the static call wrapper amd_pstate_get_epp) return u8 or s16. This makes it
difficult to correctly propagate negative error values returned by the
underlying MSR read or CPPC helpers (such as rdmsrq_on_cpu or
cppc_get_epp_perf).

Modify the return type of these functions to int, allowing them to return
negative error codes properly.

Additionally, in amd_pstate_epp_cpu_init(), fetch the firmware-programmed
default EPP value and validate it before assigning it to the EPP variables.
If amd_pstate_get_epp() returns an error code, propagate the error and abort
the CPU initialization to prevent subsequent configuration failures.

Fixes: 555bbe67a6 ("cpufreq/amd-pstate: Convert all perf values to u8")
Assisted-by: Antigravity:gemini-3.5-flash
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Marco Scardovi <scardracs@disroot.org>
Reviewed-by: K Prateek Nayak <kprateek.anayk@amd.com>
Link: https://lore.kernel.org/r/20260609073042.81275-2-scardracs@disroot.org
Signed-off-by: Mario Limonciello <superm1@kernel.org>

...

This commit is contained in:

Marco Scardovi 2026-06-09 09:29:03 +02:00 • committed by Mario Limonciello

parent 8d31bb1451

commit 57476909c3

1 changed files with 12 additions and 4 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

16

drivers/cpufreq/amd-pstate.c

View file