Messages in this thread | | | Date | Sat, 11 Sep 2004 09:19:54 +0200 (MEST) | From | Geert Uytterhoeven <> | Subject | Re: [Linux-fbdev-devel] fbdev broken in current bk for PPC |
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On Fri, 10 Sep 2004, Antonino A. Daplas wrote: > On Friday 10 September 2004 10:23, Benjamin Herrenschmidt wrote: > > Recent changes upstream are breaking fbdev on pmacs. > > > > I haven't had time to go deep into that (but I suspect Linus sees it > > too on his own g5 unless he removed offb from his .config). > > > > From what I see, it seems that offb is kicking in by default, reserves > > the mmio regions, and then whatever chip driver loads can't access them. > > > > offb is supposed to be a "fallback" driver in case no fbdev is taking > > over, it should also be "forced" in with video=ofonly kernel command > > line. This logic has been broken. > > Actually, I was thinking about this problem with offb. I was planning on > adding video=offb:off support for offb, and then place offb at the very top > drivers Makefile (the reason why I placed it there, but forgot to add the > setup support for offb). So, without the 'off' option, offb becomes the > first driver that gets initialized by reason that it's at the top, and with > the 'off' option, it just exits initialization immediately, giving the other > drivers a chance to get through.
This is not suitable, since for dual-headed machines, you may want to have one card driven by its native driver, and the other by offb (as fallback, because no driver exists yet).
> The second method is not harder but will involve, again, changes to all > drivers. The only sane method I can think of is to change fb_get_options so > it returns an error if: > > a. "off" option is enabled > b. "ofonly" is enabled but only if name != "offb" > > If fb_get_options returns an error, drivers will not proceed with their > initialization. The second method is more compatible with the > previous setup semantics.
Yes, looks better (except that it's less clean, but I'm afraid we can't fix that easily).
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
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