https://bugzilla.kernel.org/show_bug.cgi?id=78111
Bug ID: 78111 Summary: APU turbo core boost not working when radeon.dpm=1 Product: Drivers Version: 2.5 Kernel Version: 3.14.6 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: bgz.marko@gmail.com Regression: No
I am testing with A6-1450 APU on Arch Linux. If I pass radeon.dpm=1 parameter at boot and start a single core workload then turbostat will report max frequency of about 1000 MHz:
Core CPU Avg_MHz Bzy_MHz TSC_MHz time - - 262 998 998 5** 0 0 12 998 998 5** 1 1 998 998 998 2 2 16 998 998 3 3 21 998 998
"cpupower frequency-info" reports that boost state support is supported, but not active:
boost state support: Supported: yes Active: no
However, when dynamic power management is disabled (radeon.dpm=0), turbostat reports higher frequencies for single core load, up to 1300 Mhz:
Core CPU Avg_MHz Bzy_MHz TSC_MHz time - - 320 1214 998 5** 0 0 9 1226 998 5** 1 1 13 1194 998 2 2 41 1143 998 3 3 1216 1216 998
"cpupower frequency-info" confirms that boost is now active.
boost state support: Supported: yes Active: yes