[Bug 67982] New: After boot, the APU is powered with its maximum voltage (trinity/ARUBA)

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=67982

          Priority: medium
            Bug ID: 67982
          Assignee: dri-devel at lists.freedesktop.org
           Summary: After boot, the APU is powered with its maximum
                    voltage (trinity/ARUBA)
          Severity: normal
    Classification: Unclassified
                OS: Linux (All)
          Reporter: laszlo.kertesz at gmail.com
          Hardware: x86-64 (AMD64)
            Status: NEW
           Version: DRI CVS
         Component: DRM/Radeon
           Product: DRI

Created attachment 83926
  --> https://bugs.freedesktop.org/attachment.cgi?id=83926&action=edit
Dmesg

I have Debian Testing 64-bit with the latest git mesa, xf86-ati, libdrm and
kernel 3.11 installed on a A8-5500 Trinity APU.

Watching the sensors output right after logging in, i noticed that the voltage
regulation doesnt actually work initially as the APU is powered by 1.34V
(maximum possible with the radeon driver). Nothing is going on so it should
have 0.9V (minimum voltage).

This lasts until some event - for example forcing dpms off then on or switching
vts to a  text vt and back (probably some other events like playing video or
something, but the dpms and vt switching is consistently working) makes voltage
regulation kick in and start actually working lowering the APU voltage to 0.9
if idle then adjusting according to load and temperatures.

The real problem this creates if increased temperatures - after making the
voltage regulator work, the temperatures drop by as much as 10 C degrees in a
few seconds.

For reference - my sensors output lists ~17-18 C (not real obviously, seems
that these sensors report accurately after the CPU is loaded)) CPU temperatures
when idle and powered with 0.9 V.
In contrast, right after boot and doing nothing for minutes, powered with 1.34
V i have ~26-27 C idle temperatures.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20130810/1e55cc09/attachment-0001.html>