partial success with radeon tahiti card

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

I noticed that I had overlapping problems when trying out a Radeon HD
7870 (Tahiti) on NetBSD previously.

So I tried it out again with a recent kernel and was pleasantly
surprised that I got a 4k console and X started up.

However, it never survived starting firefox. IIRC I could still move
the mouse cursor (not completely sure) but all other display updates
stopped.

Once I tried starting firefox from an SSH session but there was
nothing weird in the stdout. dmesg and /var/log/messages were fine
too, just the graphics updates stopped.

Does anyone have any ideas what could be the problem here?


One other problem I saw was when I booted the size-restricted kernel
(i.e. with the tech-x11 patch I sent recently, limiting the screen to
1920x1080), console worked fine but in X, some characters were missing
(the string "1920x1080" looked like "1 2 x1 8 " or something like
that). I don't see how that can happen, but then I know nothing about
X internals....


Both of these with a 9.99.52 kernel from today.

(I've swapped out this card again for my trusty HD 4650, which at
least works reliably in 1920x1080.)

Cheers,
 Thomas