On Fri, Aug 30, 2002 at 03:53:06PM -0700, Andrew Morton wrote:
> Diego Biurrun wrote:
> > 
> > I just tried your 2.4.19-low-latency patch on a stock 2.4.19 kernel and
> > my box oopses when I manually remove my PCMCIA modem.
> 
> Yup.  The pcmcia drivers like to call sleeping devfs functions
> from within a timer handler.  The kernel tries to perform a
> context switch in interrupt context and bugs out.  This can happen
> without the low-latency patch, but doesn't.
> 
> The fix for that is to change the (strange) deferred deregister thing
> in several of the CardServices drivers to punt the activity up to
> process context via schedule_task(), but nobody has done that yet.
> 
> Probably, you can add
> 
> 	if (in_interrupt())
> 		return;
> 
> to schedule() to make the BUGs go away.   Not using devfs makes
> them go away too - but it is not a devfs bug.

Thanks for the ultraquick reply.  I managed to get another oops trace
from within (shudder) Windows Hyperterminal, I am sending this along
just in case it may help you.  Adding the two lines you mention to
sched.c also fixed the problem.
Thank you!

Diego Biurrun