sur le rc1 pour l'instant ça ne fonctionne pas encore pour moi
$ cat /sys/kernel/debug/dri/1/radeon_pm_info
state: PM_STATE_DISABLED
default engine clock: 450000 kHz
current engine clock: 3455890 kHz
default memory clock: 600000 kHz
current memory clock: 575980 kHz
PCIE lanes: 16
ii libdrm-dev 2.4.18-2 Userspace interface to kernel DRM services -- development files
ii libdrm-radeon1 2.4.18-2 Userspace interface to radeon-specific kernel DRM services -- runtime
ii libdrm2 2.4.18-2 Userspace interface to kernel DRM services -- runtime
ii libgl1-mesa-dri 7.7-4 A free implementation of the OpenGL API -- DRI modules
ii libgl1-mesa-glx 7.7-4 A free implementation of the OpenGL API -- GLX runtime
ii xserver-xorg 1:7.5+3 the X.Org X server
ii xserver-xorg-video-ati 1:6.12.191-1 X.Org X server -- ATI display driver wrapper
ii xserver-xorg-video-intel 2:2.9.1-2 X.Org X server -- Intel i8xx, i9xx display driver
edit
~$ cat /sys/kernel/debug/dri/1/radeon_pm_info
state: PM_STATE_ACTIVE
default engine clock: 450000 kHz
current engine clock: 299530 kHz
default memory clock: 600000 kHz
current memory clock: 598500 kHz
PCIE lanes: 16
$ dmesg | grep drm
[drm] Initialized drm 1.1.0 20060810
[drm] set up 63M of stolen space
[drm] radeon kernel modesetting enabled.
[drm] radeon: Initializing kernel modesetting.
[drm] register mmio base: 0xE4400000
[drm] register mmio size: 65536
[drm] Clocks initialized !
[drm] 8 Power State(s)
[drm] State 0 Default (default)
[drm] 16 PCIE Lanes
[drm] 3 Clock Mode(s)
[drm] 0 engine/memory: 450000/600000
[drm] 1 engine/memory: 450000/600000
[drm] 2 engine/memory: 450000/600000
[drm] State 1 Performance
[drm] 16 PCIE Lanes
[drm] 3 Clock Mode(s)
[drm] 0 engine/memory: 300000/300000
[drm] 1 engine/memory: 300000/500000
[drm] 2 engine/memory: 450000/600000
[drm] State 2 Battery
[drm] 16 PCIE Lanes
[drm] 3 Clock Mode(s)
[drm] 0 engine/memory: 300000/300000
[drm] 1 engine/memory: 300000/300000
[drm] 2 engine/memory: 300000/300000
[drm] State 3 Default
[drm] 16 PCIE Lanes
[drm] 3 Clock Mode(s)
[drm] 0 engine/memory: 450000/400000
[drm] 1 engine/memory: 450000/400000
[drm] 2 engine/memory: 450000/400000
[drm] State 4 Performance
[drm] 16 PCIE Lanes
[drm] 3 Clock Mode(s)
[drm] 0 engine/memory: 300000/600000
[drm] 1 engine/memory: 450000/600000
[drm] 2 engine/memory: 450000/600000
[drm] State 5 Battery
[drm] 16 PCIE Lanes
[drm] 3 Clock Mode(s)
[drm] 0 engine/memory: 300000/400000
[drm] 1 engine/memory: 300000/400000
[drm] 2 engine/memory: 300000/400000
[drm] State 6 Default
[drm] 16 PCIE Lanes
[drm] 3 Clock Mode(s)
[drm] 0 engine/memory: 450000/400000
[drm] 1 engine/memory: 450000/400000
[drm] 2 engine/memory: 450000/400000
[drm] State 7 Default
[drm] 16 PCIE Lanes
[drm] 3 Clock Mode(s)
[drm] 0 engine/memory: 300000/400000
[drm] 1 engine/memory: 300000/400000
[drm] 2 engine/memory: 300000/400000
[drm] radeon: dynamic power management enabled
[drm] radeon: power management initialized
[drm] Detected VRAM RAM=256M, BAR=256M
[drm] RAM width 64bits DDR
[drm] radeon: 256M of VRAM memory ready
[drm] radeon: 512M of GTT memory ready.
[drm] radeon: using MSI.
[drm] radeon: irq initialized.
[drm] GART: num cpu pages 131072, num gpu pages 131072
[drm] Loading RV710 Microcode
fb0: inteldrmfb frame buffer device
[drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0
[drm] ring test succeeded in 1 usecs
[drm] radeon: ib pool ready.
[drm] ib test succeeded in 0 usecs
[drm] Radeon Display Connectors
[drm] Connector 0:
[drm] LVDS
[drm] DDC: 0x7f68 0x7f68 0x7f6c 0x7f6c 0x7f70 0x7f70 0x7f74 0x7f74
[drm] Encoders:
[drm] LCD1: INTERNAL_UNIPHY2
[drm] Connector 1:
[drm] VGA
[drm] DDC: 0x7e40 0x7e40 0x7e44 0x7e44 0x7e48 0x7e48 0x7e4c 0x7e4c
[drm] Encoders:
[drm] CRT1: INTERNAL_KLDSCP_DAC1
[drm] Connector 2:
[drm] HDMI-A
[drm] HPD1
[drm] DDC: 0x7e50 0x7e50 0x7e54 0x7e54 0x7e58 0x7e58 0x7e5c 0x7e5c
[drm] Encoders:
[drm] DFP1: INTERNAL_UNIPHY
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] fb mappable at 0xC0141000
[drm] vram apper at 0xC0000000
[drm] size 4325376
[drm] fb depth is 24
[drm] pitch is 5632
fb1: radeondrmfb frame buffer device
[drm] Initialized radeon 2.1.0 20080528 for 0000:01:00.0 on minor 1
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00010002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00050002 00000000 at entry
[drm] Setting: e: 30000 m: 30000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
[drm] Requested: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at entry
[drm] Setting: e: 45000 m: 60000 p: 16
[drm] not in vbl for pm change 00020002 00000000 at exit
en fait si ça aurais l'air de fonctionner
laurent@debian:~$ cat /sys/kernel/debug/dri/1/radeon_pm_info
state: PM_STATE_ACTIVE
default engine clock: 450000 kHz
current engine clock: 299530 kHz
default memory clock: 600000 kHz
current memory clock: 598500 kHz
PCIE lanes: 16
un glxgears pour tester le changement de frequence
laurent@debian:~$ cat /sys/kernel/debug/dri/1/radeon_pm_info
state: PM_STATE_ACTIVE
default engine clock: 450000 kHz
current engine clock: 448870 kHz
default memory clock: 600000 kHz
current memory clock: 598500 kHz
PCIE lanes: 16
