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

[Mario Limonciello <mario.limonciello@amd.com>]

Well that's great news.

Giorvanni - are you sure you don't have a BIOS update available from 
your vendor?

I would much rather not carry a quirk like this if it has been fixed in 
latest BIOS.

On 10/7/26 13:30, Kyle Gospodnetich wrote:
> 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@amd.com> 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@kylegospodneti.ch> 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@amd.com> 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@amd.com> 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@suse.cz>
>>>>>>> ---
>>>>>>>      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);
>>>>>>
>>>>>
>>>>>
>>
>>