Re: [PATCH] cpufreq/amd-pstate: Prefix setup messages with FW_BUG

From: Dhananjay Ugwekar
Date: Fri Mar 28 2025 - 03:20:50 EST


On 3/21/2025 3:11 AM, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@xxxxxxx>
>
> To make it clearer that amd-pstate failing to setup is a problem
> with the firmware, prefix several messages with FW_BUG.
>
> Suggested-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
> drivers/cpufreq/amd-pstate.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 024d33d5e3670..0a9d6fe426d1c 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -931,13 +931,13 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
> * Check _CPC in ACPI table objects if any values are incorrect
> */
> if (min_freq <= 0 || max_freq <= 0 || nominal_freq <= 0 || min_freq > max_freq) {
> - pr_err("min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect\n",
> + pr_err(FW_BUG "min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect\n",
> min_freq, max_freq, nominal_freq);
> return -EINVAL;
> }
>
> if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq) {
> - pr_err("lowest_nonlinear_freq(%d) value is out of range [min_freq(%d), nominal_freq(%d)]\n",
> + pr_err(FW_BUG "lowest_nonlinear_freq(%d) value is out of range [min_freq(%d), nominal_freq(%d)]\n",
> lowest_nonlinear_freq, min_freq, nominal_freq);
> return -EINVAL;
> }
> @@ -1505,7 +1505,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
> return 0;
>
> free_cpudata1:
> - pr_warn("Failed to initialize CPU %d: %d\n", policy->cpu, ret);
> + pr_warn(FW_BUG "Failed to initialize CPU %d: %d\n", policy->cpu, ret);

Just thinking are we sure that we land here only through a firmware bug?

If not, we should probably use FW_WARN ?,
or
Should we add to the error message the specific firmware issue that might cause
each of the functions to fail (e.g. amd_pstate_init_perf(), amd_pstate_init_freq(),
etc).

Comments for the macros, for reference,

* FW_BUG
* Add this to a message where you are sure the firmware is buggy or behaves
* really stupid or out of spec. Be aware that the responsible BIOS developer
* should be able to fix this issue or at least get a concrete idea of the
* problem by reading your message without the need of looking at the kernel
* code.
*
* Use it for definite and high priority BIOS bugs.
*
* FW_WARN
* Use it for not that clear (e.g. could the kernel messed up things already?)
* and medium priority BIOS bugs.

> kfree(cpudata);
> return ret;
> }