From: K Prateek Nayak <kprateek.nayak@amd.com>
To: Mario Limonciello <mario.limonciello@amd.com>
Cc: Perry Yuan <perry.yuan@amd.com>,
"open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<linux-kernel@vger.kernel.org>,
"open list:CPU FREQUENCY SCALING FRAMEWORK"
<linux-pm@vger.kernel.org>
Subject: Re: [PATCH] cpufreq/amd-pstate: Loosen requirement on lowest nonlinear frequency != min freq
Date: Tue, 21 Jul 2026 08:21:54 +0530 [thread overview]
Message-ID: <1fcfa283-2233-41da-a3b8-07ef331bd03a@amd.com> (raw)
In-Reply-To: <20260715174318.18235-1-mario.limonciello@amd.com>
Hello Mario,
On 7/15/2026 11:13 PM, Mario Limonciello wrote:
> This requirement was introduced by commit 8f8b42c1fcc93 ("cpufreq:
> amd-pstate: optimize the initial frequency values verification")
> specifically to aid in debugging BIOS issues with invalid _CPC tables
> on some older systems.
>
> This requirement is too tight for new systems though as some systems
> actually have lowest nonlinear frequency identical to minimum
> frequency. Allow that combo to work.
>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Since I've not seen anyone complain about this on servers, and neither did
any of the machine I ran this on, feel free to include:
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
The "<" check should be good enough to catch any borken BIOS.
> ---
> drivers/cpufreq/amd-pstate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index a74a4cf99d22e..3d72337a33369 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1031,7 +1031,7 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
> return -EINVAL;
> }
>
> - if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq) {
> + 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",
> lowest_nonlinear_freq, min_freq, nominal_freq);
> return -EINVAL;
--
Thanks and Regards,
Prateek
prev parent reply other threads:[~2026-07-21 2:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-15 17:43 [PATCH] cpufreq/amd-pstate: Loosen requirement on lowest nonlinear frequency != min freq Mario Limonciello
2026-07-21 2:51 ` K Prateek Nayak [this message]
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