Re: [PATCH] cpufreq/amd-pstate: Supply nominal/lowest freq for TRX40-based motherboards

[Kyle Gospodnetich]

Looks like it's finally fixed with that last BIOS release, it's been years!

Platform Firmware Information
	Vendor: American Megatrends International, LLC.
	Version: 1.A4
	Release Date: 06/15/2026

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver
amd-pstate-epp

And no performance issues. Thanks!


On Wednesday, October 7th, 2026 at 11:08 AM, Mario Limonciello <mario.limonciello@xxxxxxx> wrote:

> OK, let's wait and see what happens after you upgrade.  New versions of
> FW and the behavior please.
> 
> On 10/7/26 12:43, Kyle Gospodnetich wrote:
> > Missed one,
> >
> > Release Date: 05/17/2022
> >
> >
> > On Wednesday, October 7th, 2026 at 10:36 AM, Kyle Gospodnetich <me@xxxxxxxxxxxxxxxxx> wrote:
> >
> >> AMD Ryzen Threadripper 3960X
> >> MSI TRX40-PRO-10G
> >> https://www.msi.com/Motherboard/TRX40-PRO-10G/support
> >> I am using 7C60v1A3(Beta version), I will update to the latest today -- just learning that exists.
> >> dmidecode reports that as:
> >> Vendor: American Megatrends International, LLC.
> >> Version: 1.80
> >>
> >> I've had to disable pstate with:
> >> amd_pstate.enable=0 initcall_blacklist=amd-pstate
> >>
> >> Without that my system grinds to a hault, takes upwards of 15 minutes just to hit the desktop.
> >>
> >> Thanks, let me know if anything else is needed.
> >> -Kyle Gospodnetich
> >>
> >>
> >> On Wednesday, October 7th, 2026 at 8:06 AM, Mario Limonciello <mario.limonciello@xxxxxxx> wrote:
> >>
> >>> Kyle,
> >>>
> >>> Can you please confirm more about your system?  System Model, vendor,
> >>> BIOS version, BIOS vendor, CPU model.
> >>>
> >>> Thanks,
> >>>
> >>> On 10/7/26 10:04, Kyle Gospodnetich wrote:
> >>>> Yes this does appear to be the same problem, thank you!
> >>>>
> >>>> -------- Original Message --------
> >>>> On Wednesday, 10/07/26 at 07:56 Mario Limonciello <mario.limonciello@xxxxxxx> wrote:
> >>>> + Kyle
> >>>>
> >>>> Kyle,
> >>>>
> >>>> By chance is this the same system that you were talking to me about offline?
> >>>>
> >>>>
> >>>>
> >>>> On 10/7/26 09:41, Giovanni Gherdovich wrote:
> >>>>> Some motherboard based on the TRX40 chipset has been reported to ship
> >>>>> firmware lacking lowest and nominal frequency values in the
> >>>>> _CPC ACPI package. That is, it supports CPPC V2 but not CPPC V3.
> >>>>> Firmware updates aren't available.
> >>>>
> >>>> Can you please add more information about the vendor/model of the MB, etc?
> >>>>>
> >>>>> amd-pstate requires explicit knowledge of nominal frequency, so it
> >>>>> can't load on this hardware. The driver already has a mechanism (the
> >>>>> so-called "quirks") to accommodate for missing nominal freq in ACPI
> >>>>> tables, so here we use it to match against CPU family, model, core
> >>>>> count, and BIOS version.
> >>>>
> >>>> Yeah; it's intended for this specific case of really old hardware that
> >>>> the BIOS isn't going to fix it.
> >>>>
> >>>> I don't understand why core count matters though.
> >>>>
> >>>>>
> >>>>> Signed-off-by: Giovanni Gherdovich <ggherdovich@xxxxxxx>
> >>>>> ---
> >>>>>     drivers/cpufreq/amd-pstate.c | 31 +++++++++++++++++++++++++++++++
> >>>>>     1 file changed, 31 insertions(+)
> >>>>>
> >>>>> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> >>>>> index 8bfd46d60843..532ff16dd076 100644
> >>>>> --- a/drivers/cpufreq/amd-pstate.c
> >>>>> +++ b/drivers/cpufreq/amd-pstate.c
> >>>>> @@ -145,6 +145,11 @@ static struct quirk_entry quirk_amd_7k62 = {
> >>>>>     	.lowest_freq = 550,
> >>>>>     };
> >>>>>
> >>>>> +static struct quirk_entry quirk_amd_ryzen_threadripper_3000_24c = {
> >>>>> +	.nominal_freq = 3800,
> >>>>> +	.lowest_freq = 550,
> >>>>> +};
> >>>>> +
> >>>>>     static inline u8 freq_to_perf(union perf_cached perf, u32 nominal_freq, unsigned int freq_val)
> >>>>>     {
> >>>>>     	u32 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * perf.nominal_perf, nominal_freq);
> >>>>> @@ -174,6 +179,22 @@ static int __init dmi_matched_7k62_bios_bug(const struct dmi_system_id *dmi)
> >>>>>     	return 0;
> >>>>>     }
> >>>>>
> >>>>> +static int __init dmi_matched_trx40_bios_bug(const struct dmi_system_id *dmi)
> >>>>> +{
> >>>>> +	/**
> >>>>> +	 * Match the Ryzen Threadripper 3000 series, 24-core SKU, sTRX4 socket / TRX40 chipset.
> >>>>> +	 */
> >>>>> +	if (boot_cpu_data.x86 == 0x17 &&
> >>>>> +	    boot_cpu_data.x86_model >= 0x30 && boot_cpu_data.x86_model <= 0x3F &&
> >>>>> +	    topology_num_cores_per_package() == 24) {
> >>>>
> >>>> Does the number of cores actually matter?  Do you mean to say if you
> >>>> swap the CPU to another part CPPC works?
> >>>>
> >>>>> +		quirks = dmi->driver_data;
> >>>>> +		pr_info("Overriding nominal and lowest frequencies for %s\n", dmi->ident);
> >>>>
> >>>> The BIOS bug specifically is lack of values, not invalid values, right?
> >>>> Just want to make sure I'm following this right.
> >>>>
> >>>>> +		return 1;
> >>>>> +	}
> >>>>> +
> >>>>> +	return 0;
> >>>>> +}
> >>>>> +
> >>>>>     static const struct dmi_system_id amd_pstate_quirks_table[] __initconst = {
> >>>>>     	{
> >>>>>     		.callback = dmi_matched_7k62_bios_bug,
> >>>>> @@ -184,6 +205,16 @@ static const struct dmi_system_id amd_pstate_quirks_table[] __initconst = {
> >>>>>     		},
> >>>>>     		.driver_data = &quirk_amd_7k62,
> >>>>>     	},
> >>>>> +	{
> >>>>> +		.callback = dmi_matched_trx40_bios_bug,
> >>>>> +		.ident = "AMD Ryzen Threadripper 3000",
> >>>>> +		.matches = {
> >>>>> +			DMI_MATCH(DMI_BIOS_VENDOR,  "American Megatrends International"),
> >>>>> +			DMI_MATCH(DMI_BIOS_VERSION, "2.80"),
> >>>>> +			DMI_MATCH(DMI_BIOS_DATE,    "05/17/2022"),
> >>>>> +		},
> >>>>> +		.driver_data = &quirk_amd_ryzen_threadripper_3000_24c,
> >>>>> +	},
> >>>>>     	{}
> >>>>>     };
> >>>>>     MODULE_DEVICE_TABLE(dmi, amd_pstate_quirks_table);
> >>>>
> >>>
> >>>
> 
>