Bug 208569

Summary:	Problems with Cool'n'Quiet on Ryzen CPUs
Product:	ACPI	Reporter:	Tiago Silva (tfiosilva)
Component:	Power-Processor	Assignee:	acpi_power-processor
Status:	NEW ---
Severity:	normal
Priority:	P1
Hardware:	x86-64
OS:	Linux
Kernel Version:	5.4.0-40-generic	Subsystem:
Regression:	No	Bisected commit-id:

Description Tiago Silva 2020-07-15 13:31:22 UTC

Hi everyone,

I am wondering if anybody else is experiencing some random reboots of computers with Ryzen processors. Specially when in idle (with no processor demand). This reboots are either followed by an MCE hardware error in the log files or no message is displayed. Both situations alternate.

I found a thread here relating this with some power management issue with amdgpu module driver. But I can confirm that the issue still persists with nvidia module drivers. Tested by me with RX550 and GTX1030.

The issue stops if the Cool'n'Quiet feature is turned off in the BIOS. In a search, the powernow-k8 does not support Ryzen processors and are not loaded in my system.

This solution is bad since the processor works at the maximum frequency all the time. In my case, for example, a Ryzen 7 2700 runs at 3200 MHz all the time. With Cool'n'Quiet it should run at 1500 MHz and rump up only on demand.

Please, if some additional information is necessary, give me instructions on how obtain it.