From mboxrd@z Thu Jan 1 00:00:00 1970
From: bugzilla-daemon@freedesktop.org
Subject: [Bug 67982] New: After boot, the APU is powered with its maximum
voltage (trinity/ARUBA)
Date: Sat, 10 Aug 2013 13:20:25 +0000
Message-ID:
Priority
medium
Bug ID
67982
Assignee
dri-devel@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@gmail.com
Hardware
x86-64 (AMD64)
Status
NEW
Version
DRI CVS
Component
DRM/Radeon
Product
DRI
Created attachment 83926 [details]
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.