[PATCH] i810: Add workaround for bad BIOS mode on Fujitsu laptops

[Tony Lindgren]

* Keith Packard <keithp at keithp.com> [070128 23:22]:
> On Sun, 2007-01-28 at 22:48 -0800, Tony Lindgren wrote:
> > Hi all,
> > 
> > Just hacking a bit to get the i810 modesetting driver to work on my
> > laptop :) Here are few patches.
> 
> We've started adding a list of 'quirks' to the EDID parsing stuff;
> perhaps we need a similar list of quirks for the BIOS data.

OK. Originally when trying to fix this I was thinking that the BIOS
mode should be verified against all the probed modes, and if the BIOS
mode does not match any VESA modes, then ignore the BIOS mode. But
then I noticed that the probed modes use BIOS mode for some
checks..

Maybe there should be some option to ignore BIOS mode? And then have
some quirks for known bad BIOS modes.
 
> It looks like you're just whacking the hsync values; can you describe a
> bit more verbosely what happens when you use the BIOS mode? Obviously,
> if we can fix up the driver so that the BIOS mode works, that would be
> nicer than discovering that the BIOS data is actually broken.

Yeah, the LVDS is streched out estimated 2x horizontally, vertical is
OK without the patch. Are you suggesting that the bug would be in the
BIOS mode parsing?
 
> Can the BIOS set the mode correctly?

I don't think so unless there's a bug in parsing the BIOS mode.
I guess I could try to dump the BIOS, or let me know what data
you need.

Regards,

Tony