Re: tsc: Fast TSC calibration failed with AMD B350M/Ryzen 3 2200G

From: Paul Menzel
Date: Mon Jan 07 2019 - 10:34:05 EST


Dear Thomas,


On 01/07/19 16:24, Thomas Gleixner wrote:

> On Mon, 31 Dec 2018, Paul Menzel wrote:
>
>> Linux 4.19.13 from Debian Sid/unstable logs the message below on the board MSI
>> MS-7A37/B350M MORTAR with the processor AMD Ryzen 3 2200G.
>>
>> As a result, the early time stamps do not seem to be working.
>
>>> [ 0.000000] DMI: Micro-Star International Co., Ltd. MS-7A37/B350M MORTAR (MS-7A37), BIOS 1.I0 11/06/2018
>>> [ 0.000000] tsc: Fast TSC calibration failed
>
> And the further boot log says:
>
> [ 0.036000] tsc: Unable to calibrate against PIT
> [ 0.036000] tsc: using HPET reference calibration
> [ 0.036000] tsc: Detected 3500.117 MHz processor
>
> So the quick calibration in early boot fails because the PIT seems not to
> do what the kernel expects. Nothing we can cure :(

I see. Can AMD confirm that this is the expected behavior? If yes, should
the fast TSC calibration be skipped on these devices?


Kind regards,

Paul

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature