[Intel-gfx] KMS and /dev/i2c-*

[Alexander E. Patrakov]

Hello,

I have tried the following setup on my Gentoo desktop:

linux-2.6.29 with KMS
libdrm-2.4.5
mesa-7.4_rc2
xorg-server-1.6.0
xf86-video-intel-2.6.99.902

My monitor (Samsung SyncMaster 770P) is connected via DVI and doesn't
have any buttons except "Power", and thus the only way to change its
brightness is via DDC-CI.

I was expecting to get /dev/i2c-* device nodes out of the
KMS-enabled kernel driver, and tell gddccontrol to use them to change
the brightness of my monitor. However, this command failed even to get
the EDID out of the kernel. Both /dev/i2c-0 and /dev/i2c-1 return this
piece of strace output when I run "strace ddccontrol -c dev:/dev/i2c-0":

open("/dev/i2c-0", O_RDWR)              = 3
ioctl(3, 0x707, 0xff8ac19c)             = -1 ENXIO (No such device or
address)

How can I debug this further?

-- 
Alexander E. Patrakov