https://bugzilla.novell.com/show_bug.cgi?id=378509 User lchiquitto@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c1 --- Comment #1 from Leonardo Chiquitto 2008-04-09 13:19:44 MST --- Created an attachment (id=207105) --> (https://bugzilla.novell.com/attachment.cgi?id=207105) Logged kernel call trace -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User lchiquitto@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c3 --- Comment #3 from Leonardo Chiquitto 2008-05-11 14:52:47 MST --- Finally was able to reproduce the issue and get a - hopefully now correct - call trace. BUG: spinlock recursion on CPU#1, swapper/0 lock: ffffffff8813a990, .magic: dead4ead, .owner: swapper/0, .owner_cpu: 1 Pid: 0, comm: swapper Tainted: G N 2.6.25-26-debug #1 Call Trace: [<ffffffff8020d686>] dump_trace+0xc4/0x576 [<ffffffff8020db78>] show_trace+0x40/0x57 [<ffffffff8046c564>] _etext+0x72/0x7b [<ffffffff80337a92>] spin_bug+0xa2/0xaa [<ffffffff80337b67>] _raw_spin_lock+0x42/0x133 [<ffffffff80465f90>] _spin_lock+0x9/0xb [<ffffffff88116eb7>] :usbcore:usb_hcd_unlink_urb_from_ep+0x18/0x43 [<ffffffff88154971>] :uhci_hcd:uhci_giveback_urb+0xf2/0x19d [<ffffffff881550d6>] :uhci_hcd:uhci_scan_schedule+0x5a4/0x85f [<ffffffff88156fa8>] :uhci_hcd:uhci_irq+0x13f/0x159 [<ffffffff88116d80>] :usbcore:usb_hcd_irq+0x2b/0x63 [<ffffffff80271810>] handle_IRQ_event+0x2e/0x65 [<ffffffff80272a29>] handle_fasteoi_irq+0x9d/0xdd [<ffffffff8020ebae>] do_IRQ+0x6e/0xd8 [<ffffffff8020c59d>] ret_from_intr+0x0/0x19 [<ffffffff88116ece>] :usbcore:usb_hcd_unlink_urb_from_ep+0x2f/0x43 [<ffffffff88448ab7>] :ohci_hcd:finish_urb+0x5e/0xb6 [<ffffffff88448b51>] :ohci_hcd:takeback_td+0x42/0xb5 [<ffffffff88448be4>] :ohci_hcd:dl_done_list+0x20/0x2d [<ffffffff8844aff2>] :ohci_hcd:ohci_irq+0x175/0x2c0 [<ffffffff88116d80>] :usbcore:usb_hcd_irq+0x2b/0x63 [<ffffffff80271810>] handle_IRQ_event+0x2e/0x65 [<ffffffff80272a29>] handle_fasteoi_irq+0x9d/0xdd [<ffffffff8020ebae>] do_IRQ+0x6e/0xd8 [<ffffffff8020c59d>] ret_from_intr+0x0/0x19 [<ffffffff802219d5>] native_irq_enable+0x6/0x7 [<ffffffff803d20f5>] cpuidle_idle_call+0x8d/0xc1 [<ffffffff8020b08a>] cpu_idle+0x92/0xda [<ffffffff80460c7f>] start_secondary+0x40e/0x41d I did some research and my best guess is that uhci-q.c:uhci_giveback_urb() misses calls to spin_lock_irqsave/restore(), to make sure IRQs are locally disabled when usb_hcd_unlink_urb_from_ep() is called. I wasn't able to verify if this is already always the case when uhci_giveback_urb() is called. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User gregkh@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c5 Greg Kroah-Hartman changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |NEEDINFO Info Provider| |lchiquitto@novell.com --- Comment #5 from Greg Kroah-Hartman 2008-05-12 09:27:42 MST --- odd thing is, this is an ohci device, not a uhci, device, right? Can you attach the output of 'hwinfo' to this bug so I can see what the usb topology looks like here? -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User lchiquitto@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c7 Leonardo Chiquitto changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |REOPENED Info Provider|lchiquitto@novell.com | --- Comment #7 from Leonardo Chiquitto 2008-05-12 11:09:19 MST --- Created an attachment (id=214477) --> (https://bugzilla.novell.com/attachment.cgi?id=214477) Hardware information Output of hwinfo -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 Greg Kroah-Hartman changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |gregkh@novell.com AssignedTo|kernel-maintainers@forge.provo.novell.com |oneukum@novell.com Status|REOPENED |NEW -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User jkosina@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c10 --- Comment #10 from Jiri Kosina 2008-05-21 05:44:20 MST --- Created an attachment (id=217221) --> (https://bugzilla.novell.com/attachment.cgi?id=217221) fix hcd deadlock Could you please try whether the problem goes away if you use the kernel from http://labs.suse.cz/jikos/download/bug-378509/ It has the attached patch incorporated. I still don't see from the code how this bug could be causing the traces you are seeing, but it should fix a possible deadlock in HCD IRQ path, so is worth trying. Thanks. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User lchiquitto@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c11 --- Comment #11 from Leonardo Chiquitto 2008-05-21 06:00:41 MST --- Hi Jiri, I'm using a kernel with your patch applied for some days now, and the machine doesn't hang anymore. I also double checked the path from the call trace, and couldn't find where interrupts are being enabled. As your patch reverts the changes made by commit e9df41c5c58, don't you think it's worth raising the issue on LKML, or privately with the author, before adding the patch to the OpenSUSE kernel? Thanks, Leonardo -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User jkosina@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c13 --- Comment #13 from Jiri Kosina 2008-05-21 06:04:52 MST --- (In reply to comment #11 from Leonardo Chiquitto)

I'm using a kernel with your patch applied for some days now, and the machine doesn't hang anymore.

Thanks a lot for testing!

I also double checked the path from the call trace, and couldn't find where interrupts are being enabled.

If my patch fixes the problem, then the call trace is bogus and the problem is elsewhere (the lock being used to synchronize between IRQ and non-IRQ contexts, without turning IRQs off, which could easily deadlock).

As your patch reverts the changes made by commit e9df41c5c58, don't you think it's worth raising the issue on LKML, or privately with the author, before adding the patch to the OpenSUSE kernel?

Well it doesn't revert the changes, it just fixes the locking that e9df41c5c58 introduced. I will proceed with the issue upstream. Thanks! -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User jkosina@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c14 Jiri Kosina changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |NEEDINFO Info Provider| |lchiquitto@novell.com --- Comment #14 from Jiri Kosina 2008-05-28 08:20:32 MDT --- Could you please try the kernel from http://labs.suse.cz/jikos/download/bug-378509/kernel-default-2.6.25.4-8.x86_... It doesn't contain the patch, but has lockdep lock correctness proving option enabled. The output from running this kernel on your system might give us some hint about what is wrong. Thanks. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User jkosina@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c16 --- Comment #16 from Jiri Kosina 2008-05-28 09:01:52 MDT --- (In reply to comment #15 from Leonardo Chiquitto)

Downloading it now. Doesn't the -debug kernels come with this option enabled?

Unfortunately they don't, and that's something I have been planning to discuss inside the kernel teams for quite some time already :) Thanks. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User lchiquitto@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c18 --- Comment #18 from Leonardo Chiquitto 2008-06-30 13:09:22 MDT --- Jiri, I'm sorry for not providing more input on this. I know you follow usb-devel@, but I'd like to register here the following thread that I'm just reading: http://marc.info/?l=linux-kernel&m=121415383913620&w=2 Thanks -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

https://bugzilla.novell.com/show_bug.cgi?id=378509 User lchiquitto@novell.com added comment https://bugzilla.novell.com/show_bug.cgi?id=378509#c20 Leonardo Chiquitto changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |ASSIGNED Info Provider|lchiquitto@novell.com | --- Comment #20 from Leonardo Chiquitto 2008-07-04 06:59:21 MDT --- I just saw that the fix was committed to Linus' tree (de85422b94ddb23c021126815ea49414047c13dc). Jiri, thanks for the help with this ticket. Leonardo -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.