https://bugs.freedesktop.org/show_bug.cgi?id=37841
Summary: Display distortion with powerprofile mid or low Product: DRI Version: XOrg CVS Platform: x86-64 (AMD64) OS/Version: Linux (All) Status: NEW Severity: major Priority: medium Component: DRM/Radeon AssignedTo: dri-devel@lists.freedesktop.org ReportedBy: bugreport@spambog.com
Overview: The display is distorted when power-profile low or mid is activated.
Steps to reproduce: echo low > /sys/class/drm/card0/device/power_profile or echo mid > /sys/class/drm/card0/device/power_profile
Actual Results: The display is distorted, but the system is still usable. The distortion consists of noisy flickering vertical stripes, with columns between them that look ok. When I choose powerprofile default or auto or high the distortion goes away and everything's as before.
Output of cat /sys/kernel/debug/dri/{0,64}/radeon_pm_info:
With powerprofile default: default engine clock: 500000 kHz current engine clock: 499500 kHz default memory clock: 600000 kHz current memory clock: 594000 kHz voltage: 1000 mV PCIE lanes: 16 default engine clock: 500000 kHz current engine clock: 499500 kHz default memory clock: 600000 kHz current memory clock: 594000 kHz voltage: 1000 mV PCIE lanes: 16
With powerprofile mid: default engine clock: 500000 kHz current engine clock: 124870 kHz default memory clock: 600000 kHz current memory clock: 405000 kHz voltage: 900 mV PCIE lanes: 16 default engine clock: 500000 kHz current engine clock: 124870 kHz default memory clock: 600000 kHz current memory clock: 405000 kHz voltage: 900 mV PCIE lanes: 16
With powerprofile low: default engine clock: 500000 kHz current engine clock: 124870 kHz default memory clock: 600000 kHz current memory clock: 405000 kHz voltage: 900 mV PCIE lanes: 16 default engine clock: 500000 kHz current engine clock: 124870 kHz default memory clock: 600000 kHz current memory clock: 405000 kHz voltage: 900 mV PCIE lanes: 16
With powerprofile high: default engine clock: 500000 kHz current engine clock: 499500 kHz default memory clock: 600000 kHz current memory clock: 594000 kHz voltage: 1000 mV PCIE lanes: 16 default engine clock: 500000 kHz current engine clock: 499500 kHz default memory clock: 600000 kHz current memory clock: 594000 kHz voltage: 1000 mV PCIE lanes: 16
Expected Results: No display distortion and perhaps other values in radeon_pm_info (values of mid and low profile should differ and perhaps there should have been some lanes deactivated by these profiles). Btw. there is no such problem when I use the powermanagement-features in xorg.conf (ForceLowPowerMode, ClockGating, DynamicPM) without KMS enabled.
Versions: See attached logfiles. Bug exists since power-profiles had been introduced (in kernel 2.6.34 or 2.6.35).