Most recent kernel where this bug did *NOT* occur: never used dock module before Distribution: archlinux Hardware Environment: Dell Precision M20 (pretty much Latitude D610), Dell D/ Port Replicator Software Environment: Problem Description: having dock module loaded, after pressing the 'undock' button on the port replicator cpu usage raises to 100%. Note that I am not removing the laptop from the replicator, if I do the problem (AFIR) disappears. On the other hand the problem sometimes happens when docking the laptop, too. Steps to reproduce: Put the laptop on the replicator and press the undock button on the replicators panel (might need to power it off, power on and then try). Notice the cpu usage. Try to rmmod dock module - it causes a segfault and traceback. Try to modprobe it and it causes segfault and another (different) traceback again. Both tbacks are attached.
I tried to reproduce the bug again with 2.6.20. It's still here. Again, what I had to to was just pressing the "undock" button on port replicator and keep the latop plugged into it (i.e. not remove it). After some time (or a couple more button pressings) kacpid process raises its cpu usage to ~90%. Again, both rmmoding and modprobing the dock module causes errors.
Created attachment 11276 [details] dmesg's output after pressing the 'undock button' twice and then rmmodding the dock module and modprobing it.
Maybe you can collect alt-sysrq-t traces while the system goes into 100% cpu busy state, could be revealing if there is any locking issue, and some race condition afterwards that causes oops/panics. 2 consequential traces will be great because one can see better which processes are stuck. Thanks.
Hi, Dawid Will you please try the latest kernel and see whether the problem still exists ? After the system is booted, please attach the output of acpidump and dmesg. It will be great if the debug function of acpi is enabled in kernel configuration. Thanks.
Created attachment 14141 [details] Tracebacks, dmesg, etc. I tested with 2.6.23.12, the problem is still here, with one difference. I can now rmmod the dock module and modprobe it back without problems. Moreover, after doing that system goes back to normal state, i.e. the cpu usage drops and everything seems working fine and usable again. However, I attach the tracebacks and outputs as you asked. syslog_after_2_consecutive_sysrq_t_tracebacks.out - file contains combined dmesg, syslog and tracebacks output. The undock button is pressed at 00:02:49, first alt-sysrq-t traceback taken at 00:04:16, second one at 00:04:50. As I mentioned above, rmmmoding dock module and modprobing it back causes no errors - simple "Dec 22 00:08:34 kromka ACPI: ACPI Dock Station Driver" shows up in dmesg.
Created attachment 14142 [details] acpidump taken soon after booting up
Created attachment 16033 [details] debug patch can you please try latest base kernel? If it doesn't work, try attached debug patch.
No response, reject it.
Hi. Sorry, I didn't notice the patch. I am currently however unable to test it as I don't have dock station here until the begining of October. I would be glad if someone else could test it though.