https://bugs.freedesktop.org/show_bug.cgi?id=38917
Summary: [patch] Radeon clocks should not be limited to defaults Product: DRI Version: unspecified Platform: Other OS/Version: Linux (All) Status: NEW Severity: normal Priority: medium Component: DRM/Radeon AssignedTo: dri-devel@lists.freedesktop.org ReportedBy: ahlaht@gmail.com
Created an attachment (id=48691) --> (https://bugs.freedesktop.org/attachment.cgi?id=48691) Do not limit clocks.patch
As of Linux 3.0-rc5 radeon_set_power_state() does not accept clock speeds higher than the defaults set by firmware. However on my HP laptop the default clock speeds are much lower than the maximum speeds accepted by the card.
These are the default values on my HP laptop: engine 100000 kHz, memory 157000 kHz, vddc 900 mV
And the other values:
echo low > power_profile power_state 4, clock_mode 0, engine 100000, memory 150000, vddc 900
echo mid > power_profile power_state 4, clock_mode 1, engine 100000, memory 150000, vddc 900
echo high > power_profile power_state 1, clock_mode 2, engine 100000, memory 157000, vddc 1000
The problem occurs with the "high" profile and also when using "dynpm". See the provided patch, it fixes the problem. With the patch applied, correct frequencies are set:
echo high > power_profile power_state 1, clock_mode 2, engine 550000, memory 800000, vddc 1000
Now the question remains: why where those checks added in the first place? They don't make sense to me unless default clock speeds are specified to be the highest possible. Also there is no such check for voltage.
I do not know if this patch can break some other already broken systems, but it's important to fix the problem somehow because it severely limits 3d performance.
The hardware is AMD Mobility Radeon HD 5650 (1002:68C1).
I'm attaching a complete list of power states on this system. Also for reference here are the values used by Windows 7 when on AC power (I forgot to test battery power):
Win 7 Catalyst PowerPlay disabled: engine 100000, memory 157000, vddc 900
Win 7 Catalyst PowerPlay enabled: engine 100000, memory 150000, vddc 900 GPU idle engine 450000, memory 800000, vddc 950 Light load engine 550000, memory 800000, vddc 1000 Heavy load
The last 2 modes here are identical to what dynpm uses on Linux after the patch.