Sur ma config les effets du paramètre radeon.dynpm=1 ne sont pas évidents :
Linux azerty 2.6.33.4-96.fc13.x86_64 #1 SMP Mon May 17 06:41:32 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux
SANS le paramètre radeon.dynpm=1
[ 9.818] Kernel command line: ro root=/dev/mapper/vg_lxdidier00-lv_root rd_LVM_LV=vg_lxdidier00/lv_root rd_LVM_LV=vg_lxdidier/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=fr_FR.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=fr-latin9 rhgb quiet
[ 9.835] (II) Primary Device is: PCI 01@00:00:0
[ 9.835] (II) [KMS] Kernel modesetting enabled.
AVEC le paramètre radeon.dynpm=1
[ 9.509] Kernel command line: ro root=/dev/mapper/vg_lxdidier00-lv_root rd_LVM_LV=vg_lxdidier00/lv_root rd_LVM_LV=vg_lxdidier/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=fr_FR.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=fr-latin9 rhgb quiet radeon.dynpm=1
[ 9.527] (II) Primary Device is: PCI 01@00:00:0
[ 9.527] (II) [KMS] drm report modesetting isn't supported.
[ 9.806] (II) RADEON(0): Dynamic Power Management Disabled
enfin AVEC le paramètre radeon.dynpm=0
[ 9.459] Kernel command line: ro root=/dev/mapper/vg_lxdidier00-lv_root rd_LVM_LV=vg_lxdidier00/lv_root rd_LVM_LV=vg_lxdidier/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=fr_FR.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=fr-latin9 rhgb quiet radeon.dynpm=0
[ 9.478] (II) Primary Device is: PCI 01@00:00:0
[ 9.478] (II) [KMS] drm report modesetting isn't supported.
[ 9.749] (II) RADEON(0): Dynamic Power Management Disabled
Donc dès que je spécifie radeon.dynpm dans mes paramètres de boot KMS est disabled.
Edit:
https://bugzilla.redhat.com/show_bug.cgi?id=593225