With 2.6.16-rc6[-git1] I get "irq 7: nobody cared" error followed by
"Disabling IRQ #7". I could not identify a way of reproducing it, it
just happens at any given time after boot. As suggested by error, I
booted with "irqpoll" option, but that did not solve the problem. Worse
yet, it managed to take my system down while spitting "hdc:
cdrom_pc_intr: The drive appears confused (ireason = 0x01)" errors.

IRQ 7 belongs to two USB ports. When I initially noticed the error with
2.6.16-rc6, there were no devices connected and "usblp" module was not
built. With 2.6.16-rc6-git1, which had "usblp" built, the behavior is
identical.

The last kernel, before these, on this machine was 2.6.16-rc5-git1 which
did not seem to exhibit such errors, but 2.6.16-rc5, it currently runs,
does.

I have been using dyn-ticks for some time and strangely enough, the
error appeared after I stopped using it. This might also be only a
coincidence.

I did not try any version above 2.6.16-rc6-git1, so I cannot claim this
is not fixed, but I will probably only be able to do it some time next week.

I am not experienced in kernel debugging, but I tried to gather as much
useful information as I could. If there is something obvious I have
missed, please say so. I am very confused about all of this, and my only
hope is that this is not a hardware failure.

This is my first mail to LKML. I am not subscribed, please CC me.

Regards,
Linas