Bug 21721

Bug description:
When using kernel mode setting and UXA acceleration, Xv cannot be enabled. 

Important Xorg.log part: 
(II) intel(0): Attempting memory allocation with tiled buffers.
(EE) intel(0): Failed to set tiling on front buffer: Invalid argument
(II) intel(0): Tiled allocation successful.
(WW) intel(0): Disabling Xv because no adaptors could be initialized. 

System environment:
-- chipset: Intel Corporation 82801DBM (ICH4-M)
-- system architecture: IA32
-- xf86-video-intel: 2.7.99.1 (and 2.7.0)
-- xserver: 1.6.1
-- mesa: 7.4.1 intel-dri
-- libdrm: 2.4.9
-- kernel: Linux cruss 2.6.30-rc5 #54 PREEMPT Tue May 12 17:32:48 CEST 2009 i686 Intel(R) Pentium(R) M processor 1.70GHz GenuineIntel GNU/Linux
-- Linux distribution: archlinux(.org)
-- Machine or mobo model: Dell Latitude D500, ICH4
-- Display connector: Intel Corporation 82852/855GM Integrated Graphics Device

Reproducing steps:
1) startx
2) xvinfo

Additional info:
1) Option "Tiling" "off" eleminates tiling error, but does not help enabling Xv, but it seems to disable XvMC.
2) In every case xvinfo shows:
--X-Video Extension version 2.2
--screen #0
-- no adaptors present
3) Since my machine uses KMS dmesg shows this a few times when X is used.
i2c-adapter i2c-0: unable to read EDID block.
i915 0000:00:02.0: VGA-1: no EDID data

Xorg.log will be attached.