hand-rolled kernels sometimes work, sometimes not

[Robert P. J. Day]

On Sat, 25 Dec 2010, Robert P. J. Day wrote:

>
>   i'm having a bit of frustration with building and booting to new
> kernels i build from the latest git pull.
>
>   not that long ago, i built a new kernel from something like the
> 2.6.37-rc1 git tree.  i used the (at that time) ubuntu config file as
> a starting point and built the new kernel, then (if memory serves)
>
>   * make modules_install
>   * make install
>   * update-initramfs -c -k <kernel version>
>   * update-grub
>
> but when i booted that kernel, what i got was a pitch-black display,
> even though it was obvious the system was booting (much disk
> activity).  nothing i did could get me a display (virtual consoles
> didn't work).  so i gave up and stuck with the shipped ubuntu kernel.
>
>   come 2.6.37-rc5 and i gave it another try, same recipe and, holy
> crap, it booted fine, everything worked.  no idea why it was different
> but, since then, i've been running off my hand-rolled 2.6.37-rc5+
> kernel.
>
>   and today, i figured, let's try it one more time.  2.6.37-rc7 git
> pull, go thru the same recipe, reboot and ... blank.  what i get is
> two opening lines:
>
>   mounting /dev/pts failed, busy
>   ureadahead ... blah blah ...
>
> nothing unusual, what i'm used to, the display goes black, then the
> backlight kicks in and ... that's it.  still much disk activity and if
> i wait long enough, i can even hear the cute little drum roll as the
> gnome desktop gives me my login prompt, but absolutely nothing on the
> screen.
>
>   so it's gone from not working, to working, to not working again.  i
> used the same kernel config file for this build as for the earlier
> working one, so i am at a loss as to what the heck is going on, and
> i'm open to suggestions.

  ok, things just got worse.  i went back and selected the latest
ubuntu-supplied kernel -- 2.6.35-23-generic -- and *that* one failed
as well.  early in the boot process, i got a *very* brief glimpse of
something like "i915 graphics turbo disabled" or something like that,
after which total darkness. so i'm now in the position of having what
looks like precisely *one* working kernel, which i rolled myself and
which works for no reason that i know of (and which is the kernel i'm
running right now).

  i am very nervous at this point.

rday

p.s.  this is a gateway NV79 laptop.