Regression 2.6.34+ -> 2.6.34-rc5: radeon KMS rs780 problems

[Ed Tomlinson <edt@aei.ca>]

Hi,

My 790gx chipset supplies an rs780.  With .34+ all is ok.  With .35-rc5 basic function seems ok (kde works) but
games like extreme tux racer have problems.  The cursor does not display when on the tux racer window and
various objects flicker on and off as I attempt to play the game.   

Here is what .34+ detects (think this kernel has a drm-radeon-testing from may or early june)

[    1.370735] [drm] Initialized drm 1.1.0 20060810
[    1.376014] [drm] radeon defaulting to kernel modesetting.
[    1.382041] [drm] radeon kernel modesetting enabled.
[    1.387560] radeon 0000:01:05.0: PCI INT A -> GSI 18 (level, low) -> IRQ 18
[    1.395205] radeon 0000:01:05.0: setting latency timer to 64
[    1.397347] [drm] initializing kernel modesetting (RS780 0x1002:0x9614).
[    1.404961] [drm] register mmio base: 0xFE9F0000
[    1.410036] [drm] register mmio size: 65536
[    1.415328] ATOM BIOS: B27722
[    1.418612] [drm] Clocks initialized !
[    1.422740] [drm] 3 Power State(s)
[    1.426486] [drm] State 0 Default (default)
[    1.431081] [drm]    1 Clock Mode(s)
[    1.434831] [drm]            0 engine: 300000
[    1.438773] [drm] State 1 Performance
[    1.442897] [drm]    1 Clock Mode(s)
[    1.446648] [drm]            0 engine: 500000
[    1.450589] [drm] State 2 Default
[    1.454344] [drm]    1 Clock Mode(s)
[    1.458093] [drm]            0 engine: 500000
[    1.462038] [drm] radeon: power management initialized
[    1.467705] radeon 0000:01:05.0: VRAM: 256M 0xC0000000 - 0xCFFFFFFF (256M used)
[    1.475724] radeon 0000:01:05.0: GTT: 512M 0xA0000000 - 0xBFFFFFFF
[    1.485117] [drm] Detected VRAM RAM=256M, BAR=256M
[    1.490391] [drm] RAM width 32bits DDR
[    1.494785] [TTM] Zone  kernel: Available graphics memory: 3956838 kiB.
[    1.502042] [TTM] Zone   dma32: Available graphics memory: 2097152 kiB.
[    1.509465] [drm] radeon: 256M of VRAM memory ready
[    1.514825] [drm] radeon: 512M of GTT memory ready.
[    1.520236] [drm] radeon: irq initialized.
[    1.524739] [drm] GART: num cpu pages 131072, num gpu pages 131072
[    1.532253] [drm] Loading RS780 Microcode

with .35-rc5 it finds a different ammount of VRAM.  Hardware wise there is 128M of sideport ram.

 [    1.361622] [drm] Initialized drm 1.1.0 20060810
 [    1.366843] [drm] radeon defaulting to kernel modesetting.
 [    1.372863] [drm] radeon kernel modesetting enabled.
 [    1.378371] radeon 0000:01:05.0: PCI INT A -> GSI 18 (level, low) -> IRQ 18
 [    1.386003] radeon 0000:01:05.0: setting latency timer to 64
 [    1.388242] [drm] initializing kernel modesetting (RS780 0x1002:0x9614).
 [    1.395870] [drm] register mmio base: 0xFE9F0000
 [    1.400940] [drm] register mmio size: 65536
 [    1.406238] ATOM BIOS: B27722
 [    1.409531] [drm] Clocks initialized !
 [    1.413688] radeon 0000:01:05.0: VRAM: 384M 0xC0000000 - 0xD7FFFFFF (384M used)
 [    1.421706] radeon 0000:01:05.0: GTT: 512M 0xA0000000 - 0xBFFFFFFF
 [    1.429481] [drm] Detected VRAM RAM=384M, BAR=256M
 [    1.436429] [drm] RAM width 32bits DDR
 [    1.440829] [TTM] Zone  kernel: Available graphics memory: 3956866 kiB.
 [    1.448096] [TTM] Zone   dma32: Available graphics memory: 2097152 kiB.
 [    1.455348] [TTM] Initializing pool allocator.
 [    1.460471] [drm] radeon: 384M of VRAM memory ready
 [    1.465824] [drm] radeon: 512M of GTT memory ready.
 [    1.471255] [drm] radeon: irq initialized.
 [    1.475760] [drm] GART: num cpu pages 131072, num gpu pages 131072
 [    1.483280] [drm] Loading RS780 Microcode

User space/firmware/bios is the same in both cases.

Idea?
Ed Tomlinson