Re: 2.6.23-rc7 + radeonfb/s2ram

[Mihai Donțu <mihai.dontu@gmail.com>]

On Sunday 23 September 2007, Mihai Donțu wrote:
> On Sunday 23 September 2007, Benjamin Herrenschmidt wrote:
> > Heh, yup.
> > 
> > There have been some radeonfb patches around -rc6 or so. Can you try
> > backing them out and letting us know if that helps a) ?
> > 
> > In that case, Linus, we probably want to revert them...
> > 
> > Though looking at your PCI ID (5955), I don't think the patches should
> > have changed anything.
> 
> After four hours of bisecting, I got this, which dates back to 2.6.21, but
> I've been on 2.6.21.3 for too long and thus missed the commit (I just decided
> to be a good citizen and test things before they get out).
> 
> dd1447134454b169d5ae353aceb93f2368db8547 is first bad commit
> commit dd1447134454b169d5ae353aceb93f2368db8547
> Author: johan henriksson <jhn98032@gmail.com>
> Date:   Tue May 8 00:37:59 2007 -0700
> 
>     radeonfb: Add support for Radeon xpress 200m
> 
>     Added support for radeon xpress 200m(rs480).  Note that the card doesn't
>     like dynclk turned on.
> 
>     Signed-off-by: Johan Henriksson <jhn98032@gmail.com>
>     Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>     Cc: "Antonino A. Daplas" <adaplas@pol.net>
>     Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> 
> :040000 040000 e553664a656ee329152789818b5b071a36ac1e45 0a698ad7daa8cdfd9eb5304812845306c9feb2f9 M      drivers
> 
> I turned dynclk off, no result (although dynclk is preferred).
> 
> What is interesting, is that the driver ignores "vga=normal" and "jumps" to
> a quite high res (I think is 1024x768 or something; the fonts look really nice
> though :)).

  Something strange is going on here: after I cleaned up the bisect kernels,
  I booted 2.6.23-rc7 using something like:
  "vga=normal nohz=on root=/dev/sda7 libata.noacpi=0 pci=assing-busses"
  and explicitly selecting "Enable Video Mode Handling Helpers" (which normally
  gets automatically selected once I choose "ATI Radeon display support" but I
  - suffering from intense paranoia - selected it by hand prior to selecting ATI
  Radeon ...).

  I works! X is no longer acting weird. I can't use "vga=791" anymore (the screen
  goes blank until X loads => timings definitely changed) but it *works* and I don't
  know why _and_ I can't seem to be able to make it go back to being bad :)
  
  I did a diff between the .config used in bisect and the current .config. I don't
  see anything suspicious.

  I'll to do a full cleanup and start all over. I'm going to nail this thing down if
  it's the last thing I do! (so help me God) :)

-- 
Mihai Donțu
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