On 11/5/2014 5:50 PM, Guenter Roeck wrote:
On Wed, Nov 05, 2014 at 06:34:20PM -0500, James Cloos wrote:
> "GR" == Guenter Roeck linux@roeck-us.net writes:
... GR> AMD CPUs are known report wildly off temperatures especially at GR> low temperatures.
Thanks. After some further digging, I wonder whether Aravind's recent patch might help? The apu does have both PCI_DEVICE_ID_AMD_16H_M30H_NB_F3 and PCI_DEVICE_ID_AMD_16H_M30H_NB_F4 and lspci reports no driver for the F4 device.
Aravind would have to comment; my understanding is that the F4 device reports the power, not the temperature. You could try to apply the patch and see if it makes a difference. Worst case there will be no change ;-).
Right, F4 is for reporting power values. The recent patch was a bug fix for fam15h_power, so I don't think that's what you are looking for..
GR> Does the temperature increase with load ?
It seems to max out w/in a kelvin or two of the room's ambient temp.
Even under load ? Sounds weird.
Yeah, I have not come across such odd behavior neither. So not able to tell you what might be wrong..
Question of course is if the chip really reports a useful temperature in the first place; this is something I can not answer, since I have neither a datasheet nor a system with that CPU.
Yes, the values reported are accurate and AFAIK there are folks who are interested to look into temperature/power values reported by hwmon, so I guess it's useful :) I shall try and ask around if someone knows anything about incorrect values being exposed in the registers and let you know.
Thanks, -Aravind