Re: LCD sync rates
> > > If the X server locks up, you can
> > > always use alt+sysrq+u, alt+sysrq+b
> >
> > Magic sysrq's might only work at a console prompt. cf above, your keyboard
> > may be inoperable.
>
> No, they always work, since it's all in the kernel, before it goes
> through the "keyboard mode" stuff that kbdmode messes with. That
> being the case, it doesn't matter if X is running and has your
> keyboard in raw mode. You obviously don't see the output from your
> keystrokes, but they show up in the kernel log messages, even
> alt+sysrq+?.
Hmm. Well, sysrq still needs to be turned on. (Here's where I can't
tell you a good debian answer, since I usually build my own kernels)
> Err, one other thing that can bring down alt+sysrq: The system could
> deadlock with interrupts disabled, in which case you lose, and nothing
> will ever get through, not ethernet, not mouse, not keyboard, not
> serial. I don't think X can disable interrupts, though, so as long as
> the kernel isn't buggy, you're fine (he says optimistically... :)
>
> Anyway, we both agree that logging in remotely is the way to go. I
> was just pointing out that, especially for this problem, you can get
> away with not doing that if you can deal with the system when it's
> having problems. (For the display-won't-sync problem,
> nothing is going to happen that overwrites the kernel in memory or
> whatever, so it's unlikely that the system will hang and require a
> reboot.)
Not unless you try to give X some exceedingly stupid options, anyway.
My hubby once had to give X some directions about where video memory
was really located. Mistyped. The hard disk controller he hit instead
was *really* unhappy. Only had to fsck 6 times to clean everything up.
But, these are laptops, you shouldn't be doing *THAT* :)
If interrupts are deadlocked you'll probably lose the network too. It
just depends.
* Heather Stern * star@ many places...
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