Re: [PATCH] reset VGA adapters via BIOS on resume... (non-fbdev/con)

[Pavel Machek]

Hi!

> > 	At OLS at lot of people were giving out about cards not resuming,
> > so using a patch from Michael Marineau and help from lots of people
> > sitting around in a circle at OLS I've gotten a patch that restores video
> > on my laptop by going into real mode and re-posting the BIOS during
> > resume,
> 
> On laptops, the code at c000:0003 may jump to BIOS code that isn't
> present after system boot. In userspace, this isn't too much of a
> problem - the userspace code tends to just fall over rather than hanging
> the machine. What happens if the kernel hits illegal or inappropriate
> code on resume?
> 
> I'm still fairly convinced that the best approach here is to carry it
> out in userspace, though this may require some support for asking
> framebuffers not to try to print anything until userspace is running.
> The only "real" solution is for the framebuffer drivers to know how to
> program the chip from scratch.

Unfortunately, if you only get printk() working after you ran
userspace app... well it makes debugging things like SATA
"interesting". So I quite like this patch.

If your BIOS does something wrong, well... your machine crashes.

							Pavel
-- 
teflon -- maybe it is a trademark, but it should not be.
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