Created an attachment (id=5905)
Xorg log file from the run with the patched radeon kernel driver

Sorry, that it took so long. I had to fight quite a lot of kernel oopses when
unloading the module. Actually unloading wasn't possible at all, so I had to
reboot the system several times.

Just to make sure that I am not doing something wrong, here is my workflow:

- download drm from cvs as described by dri.freedesktop.org/wiki/Download
- goto drm/shared-core
- download your patch, name it wb.pl
- apply it with "patch < wb.pl" -> no errors reported, two files patched
- goto drm/linux-core
- apply "make", no errors
- leave kde, switch to console, enter runlevel 3
- mv old modules from
/lib/modules/2.6.16.16-kanotix-up-1/kernel/drivers/char/drm/ to some other
place
- cp new radeon.ko and drm.ko
- apply "depmod -a"
- unload old modules: "rmmod radeon; rmmod drm" (or just reboot into runlevel
3)
- load new modules: "modprobe radeon no_wb=1"
- enter runlevel 5

dmesg shows:
Jun 14 12:38:33 LaptopMB kernel: [drm] Initialized drm 1.0.1 20051102
Jun 14 12:38:33 LaptopMB kernel: PCI: Unable to reserve mem region
#1:8000000@e0000000 for device 0000:01:00.0
Jun 14 12:38:33 LaptopMB kernel: ACPI: PCI Interrupt 0000:01:00.0[A] -> Link
[LNKA] -> GSI 11 (level, low) -> IRQ 11
Jun 14 12:38:33 LaptopMB kernel: [drm] Initialized radeon 1.25.0 20060524 on
minor 0: 
Jun 14 12:38:33 LaptopMB kernel: [drm] Used old pci detect: framebuffer loaded
Jun 14 12:38:58 LaptopMB init: Switching to runlevel: 5
Jun 14 12:38:58 LaptopMB kernel: capifs: Rev 1.1.2.3
Jun 14 12:39:00 LaptopMB kernel: agpgart: Found an AGP 2.0 compliant device at
0000:00:00.0.
Jun 14 12:39:00 LaptopMB kernel: agpgart: Putting AGP V2 device at 0000:00:00.0
into 1x mode
Jun 14 12:39:00 LaptopMB kernel: agpgart: Putting AGP V2 device at 0000:01:00.0
into 1x mode
Jun 14 12:39:00 LaptopMB kernel: [drm] Setting GART location based on new
memory map
Jun 14 12:39:00 LaptopMB kernel: [drm] writeback test succeeded in 2 usecs
Jun 14 12:39:00 LaptopMB kernel: [drm] writeback forced off

cat /proc/acpi/processor/CPU/power:
active state:		 C2
max_cstate:		 C8
bus master activity:	 32622151
states:
    C1: 		 type[C1] promotion[C2] demotion[--] latency[000]
usage[00000010]
   *C2: 		 type[C2] promotion[C3] demotion[C1] latency[001]
usage[00101866]
    C3: 		 type[C3] promotion[--] demotion[C2] latency[085]
usage[00000000]

When unloading the module, I get a kernel oops:

Jun 14 12:33:31 LaptopMB kernel: Unable to handle kernel NULL pointer
dereference at virtual address 00000000
Jun 14 12:33:31 LaptopMB kernel:  printing eip:
Jun 14 12:33:31 LaptopMB kernel: f938a58f
Jun 14 12:33:31 LaptopMB kernel: *pde = 00000000
Jun 14 12:33:31 LaptopMB kernel: Oops: 0000 [#1]
Jun 14 12:33:31 LaptopMB kernel: PREEMPT
Jun 14 12:33:31 LaptopMB kernel: Modules linked in: radeon drm arc4
ieee80211_crypt_wep capifs rfcomm l2cap bluetooth therm
al fan button battery ac usblp af_packet xt_tcpudp xt_state ip6table_filter
ip6_tables ipv6 iptable_filter ip_tables x_tabl
es ip_conntrack_tftp ip_conntrack_proto_sctp ip_conntrack_pptp
ip_conntrack_netlink ip_nat ip_conntrack_netbios_ns ip_connt
rack_irc ip_conntrack_ftp ip_conntrack_amanda ip_conntrack nfnetlink cdemu
ibm_acpi nvram speedstep_centrino freq_table pro
cessor hw_random pcmcia eth1394 tsdev snd_intel8x0 snd_ac97_codec snd_ac97_bus
snd_pcm_oss snd_mixer_oss snd_pcm irtty_sir
snd_timer psmouse sir_dev yenta_socket ipw2100 8250_pci shpchp pci_hotplug
intel_agp agpgart snd soundcore snd_page_alloc s
erio_raw irda pcspkr ohci1394 ieee1394 rsrc_nonstatic pcmcia_core i2c_i801
ieee80211 ieee80211_crypt 8250_pnp 8250 serial_c
ore e100 mii crc_ccitt parport_pc parport evdev usbmouse usbhid usbkbd uhci_hcd
ehci_hcd usbcore
Jun 14 12:33:31 LaptopMB kernel: CPU:	 0
Jun 14 12:33:31 LaptopMB kernel: EIP:	 0060:[<f938a58f>]    Not tainted VLI
Jun 14 12:33:31 LaptopMB kernel: EFLAGS: 00210246   (2.6.16.16-kanotix-up-1 #1)

Jun 14 12:33:31 LaptopMB kernel: EIP is at drm_lastclose+0xbf/0x386 [drm]
Jun 14 12:33:31 LaptopMB kernel: eax: 00000000	 ebx: cade2c00	 ecx: 00000000 
 edx: c02969f0
Jun 14 12:33:31 LaptopMB kernel: esi: cade2c00	 edi: fffffff4	 ebp: cade2ccc 
 esp: c9603f1c
Jun 14 12:33:31 LaptopMB kernel: ds: 007b   es: 007b   ss: 0068
Jun 14 12:33:31 LaptopMB kernel: Process rmmod (pid: 10822, threadinfo=c9602000
task=cad3f030)
Jun 14 12:33:31 LaptopMB kernel: Stack: <0>cade2c00 cade2c14 cade2c00 00000001
f93cbc60 c9602000 f93906ef cade2c00
Jun 14 12:33:31 LaptopMB kernel:	cade2c00 00000001 f93908ab 00000000
f93cd200 c9602000 f93c4c4a f93cbc60
Jun 14 12:33:31 LaptopMB kernel:	c013702c 65646172 ca006e6f c014ca29
ca94aac0 00100073 00000000 ffffffff
Jun 14 12:33:31 LaptopMB kernel: Call Trace:
Jun 14 12:33:31 LaptopMB kernel:  [<f93906ef>] drm_cleanup+0x1f/0x170 [drm]
Jun 14 12:33:31 LaptopMB kernel:  [<f93908ab>] drm_exit+0x6b/0xc0 [drm]
Jun 14 12:33:31 LaptopMB kernel:  [<f93c4c4a>] radeon_exit+0xa/0x16b [radeon]
Jun 14 12:33:31 LaptopMB kernel:  [<c013702c>] sys_delete_module+0x12c/0x1a0
Jun 14 12:33:31 LaptopMB kernel:  [<c014ca29>] do_munmap+0x189/0x1e0
Jun 14 12:33:31 LaptopMB kernel:  [<c0102dfb>] sysenter_past_esp+0x54/0x79
Jun 14 12:33:31 LaptopMB kernel: Code: ae f7 d1 49 8b 06 50 e8 20 e1 dc c6 c7
06 00 00 00 00 c7 46 04 00 00 00 00 58 8b 86
cc 00 00 00 8d ae cc 00 00 00 89 c1 8d 78 f4 <8b> 5f 0c 83 eb 0c 39 e8 74 47 8d
96 bc 00 00 00 89 14 24 eb 02

Except from the kernel oops, it seems that this does not affect bus mastering
activity.

If my workflow is o.k., I can try other patches.

I attached the Xorg.0.log file from the kde session after loading the module
with the no_wb=1 option.

Michael