Re: Lockup since 2.4.4 when switching from X to console

[Keith Owens <kaos@melbourne.sgi.com>]

On Tue, 28 Aug 2001 21:40:57 +0200, 
Juri Haberland <juri@koschikode.com> wrote:
>Jani Jaakkola wrote:
>
>> There are lots of motherboards around which have somewhat broken APM
>> support or at least do not work correctly with Linux APM. Many of these
>> machines just hang, when console blanking or unblanking using APM is
>> attempted. This is not XFS spesific and is not even 2.4 kernel spesific.
>
>See, the point is that with a vanilla kernel it works without a problem
>but with the kdb patch applied it locks up. So somehow the kdb patch
>breaks the apm stuff and this should be investigated and, if possible,
>resolved.

The kdb patch goes nowhere near apm.  It sounds like apm has a bug that
is sensitive to the layout of the kernel or stack,particularly since
compiling without kdb configured on still has the problem.  Did you
compile the kernel with frame pointers on or with kallsyms and does
removing those options make a difference?