Radeon driver with FC20 latest kernel update

[Andrew R Paterson]

Hi,
I am running fedora 20 X86_64

I have an Intel Processor:
Intel(R) Core(TM)2 Quad CPU Q6700 @ 2.66GHz.

I have an AMD radeon based GPU card :
Advanced Micro Devices, Inc. [AMD/ATI] RV535 [Radeon X1650 PRO] (Secondary)
(rev 9e)

I have two monitors :
ACER Technolgies – on DVI-0 (1920x1080)
Viewsonic Corporation on DVI-1 (1920x1200)

They are (were!) driven by the radeon module :

lsmod :-
.....
radeon 1496040 2
.....
i2c_algo_bit 13257 1 radeon
.....
drm_kms_helper 	89555 1 radeon
ttm 				80807 1 radeon
.....
drm 				296901 5 ttm,drm_kms_helper,radeon


/var/log/messages shows:

radeon 0000:01:00.0: VRAM: 512M 0x0000000000000000 - 0x000000001FFFFFFF (512M 
used)
radeon 0000:01:00.0: GTT: 512M 0x0000000020000000 - 0x000000003FFFFFFF
[drm] Detected VRAM RAM=512M, BAR=256M
[drm] RAM width 128bits DDR

X server log shows:

[ 88.037] (II) Loader magic: 0x80dd00
[ 88.037] (II) Module ABI versions:
[ 88.037] X.Org ANSI C Emulation: 0.4
[ 88.037] X.Org Video Driver: 14.1
[ 88.037] X.Org XInput driver : 19.2
[ 88.037] X.Org Server Extension : 7.0
[ 88.037] (II) xfree86: Adding drm device (/dev/dri/card0)
[ 88.040] (--) PCI:*(0:1:0:0) 1002:71c1:174b:0840 rev 158, Mem @ 
0xd0000000/268435456, 0xfdaf0000/65536, I/O @ 0x0000ae00/256, BIOS @ 
0x????????/131072
[ 88.040] (--) PCI: (0:1:0:1) 1002:71e1:174b:0841 rev 158, Mem @ 
0xfdae0000/65536, BIOS @ 0x????????/65536
....
....
[ 88.058] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[ 88.058] (II) FBDEV: driver for framebuffer: fbdev
[ 88.058] (II) VESA: driver for VESA chipsets: vesa
[ 88.058] (++) using VT number 1
.....
.....
[ 88.059] (II) [KMS] Kernel modesetting enabled.
[ 88.059] (WW) Falling back to old probe method for modesetting
[ 88.059] (WW) Falling back to old probe method for fbdev
[ 88.059] (II) Loading sub module "fbdevhw"
[ 88.059] (II) LoadModule: "fbdevhw"
[ 88.059] (II) Loading /usr/lib64/xorg/modules/libfbdevhw.so
[ 88.060] (II) Module fbdevhw: vendor="X.Org Foundation"
[ 88.060] compiled for 1.14.4, module version = 0.0.2
[ 88.060] ABI class: X.Org Video Driver, version 14.1
[ 88.060] (WW) Falling back to old probe method for vesa
[ 88.060] (II) RADEON(0): Creating default Display subsection in Screen 
section
"Default Screen Section" for depth/fbbpp 24/32
[ 88.060] (==) RADEON(0): Depth 24, (--) framebuffer bpp 32
[ 88.060] (II) RADEON(0): Pixel depth = 24 bits stored in 4 bytes (32 bpp 
pixmaps)
[ 88.060] (==) RADEON(0): Default visual is TrueColor
[ 88.060] (==) RADEON(0): RGB weight 888
[ 88.060] (II) RADEON(0): Using 8 bits per RGB (8 bit DAC)
[ 88.060] (--) RADEON(0): Chipset: "ATI Radeon X1650" (ChipID = 0x71c1)
.....
________________________________________________
All worked well up to kernel 3.17.7-200.fc20.x86_64.
________________________________________________

The recent update to kernel 3.17.8-200.fc20.x86_64
results in radeon.ko failing to load.

/var/log/messages shows:

[drm:radeon_init] *ERROR* No UMS support in radeon module!

%modrpobe radeon gives same message.

My monitors are then in low res mirorred mode (ugh!)

X server log shows:
....
[ 13345.844] (II) Loader magic: 0x80dd00
[ 13345.844] (II) Module ABI versions:
[ 13345.844] X.Org ANSI C Emulation: 0.4
[ 13345.844] X.Org Video Driver: 14.1
[ 13345.844] X.Org XInput driver : 19.2
[ 13345.844] X.Org Server Extension : 7.0
[ 13345.844] (II) xfree86: Adding drm device (/dev/dri/card0)
[ 13345.844] setversion 1.4 failed
[ 13345.848] (--) PCI:*(0:1:0:0) 1002:71c1:174b:0840 rev 158, Mem @ 
0xd0000000/268435456, 0xfdaf0000/65536, I/O @ 0x0000ae00/256, BIOS @ 
0x????????/131072
[ 13345.848] (--) PCI: (0:1:0:1) 1002:71e1:174b:0841 rev 158, Mem @ 
0xfdae0000/65536, BIOS @ 0x????????/65536
.......

I understand UMS is User ModeSetting – which according to a quick browse of 
the source for the radeon module means CONFIG_DRM_RADEON_UMS is not set.
Then I came across comments to the effect that this has been deprecated (a 
mysterious word akin to legal-speak!) presumably replaced by KMS.

Has anybody got any clues how I can get the radeon driver loading and working 
again?
Or even if its a bug whether it will soon be fixed?

Many Thanks

Andy