radeon driver: checkpoint

[Benjamin Herrenschmidt]

> Here are some updates. Sorry for taking so long to do that.
> 
> 1. With the current ati-1-0-branch, the mergedfb problem is gone. The 
> screen comes up nicely. The traditional 2-screens mode still doesn't 
> produce any output on the 2nd head.
> 
> 2. I installed Linux on a disk for this machine in order to be able to 
> run radeontool and get register dumps. The behaviour is the same as 
> under OpenBSD: mergedfb works well with the current ati-1-0-branch 
> driver, but no signal on 2nd head with the traditional 2-screen mode.
> X.Org 6.8.2 works in this mode (but mergedfb displays garbage).
> 
> I've attached register dumps.

Thanks !

I spotted a couple of "interesting" ones (at the very least)

-BUS_CNTL (0030)        0x5133a3b0
+BUS_CNTL (0030)        0x00000000

ARGH ! That is bad bad bad !

Can you try modifying RADEONSaveCommonRegisters()

And add:

    save->bus_cntl           = INREG(RADEON_BUS_CNTL);

to it ?

Also, I spotted:

-CRTC_EXT_CNTL (0054)   0x00008048
+CRTC_EXT_CNTL (0054)   0x00000048

RADEON_CRTC_CRT_ON is clear here, that means that the CRT is off, is
that expected ? (That is, your primary head is a flat panel ? Does it
"fixes" your problem if you use radeontool to dynamically "fix" the
value to 0x8048 (radeontool regset CRTC_EXT_CNTL 0x8048)

Also, you seem to have tiling enabled in the 7.0 dump and not the 6.82
dump, is that actually the case ?

Cheers,
Ben.