+++ This bug was initially created as a clone of Bug #222083 +++ Description of problem: Random system lockups, seems uneffected by usage or load. Version-Release number of selected component (if applicable): kernel-2.6.18-1.2869.fc6 How reproducible: Issue occurs randomly about 0 to four times a day. It has been occuring on multiple kernel versions (possibly even on FC5). Issue has appeared on 2 seperate Dell Latitude D600 laptops. Has been appearing more frequently with the use of a USB modem (cellphone teather) to access network. Steps to Reproduce: 1. Use FC6 with USB modem to access network. 2. Can use system for web browsing or leave idle 3. Actual results: System lockup Expected results: no lockup Additional info: Previously no information was attained, was finally able to reproduce issue with serial console capture. BUG: spinlock recursion on CPU#0, firefox-bin/5756 (Not tainted) lock: e51c66c8, .magic: dead4ead, .owner: firefox-bin/5756, .owner_cpu: 0 [<c04051db>] dump_trace+0x69/0x1af [<c0405339>] show_trace_log_lvl+0x18/0x2c [<c04058ed>] show_trace+0xf/0x11 [<c04059ea>] dump_stack+0x15/0x17 [<c04e978d>] _raw_spin_lock+0x35/0xdc [<f0c132f9>] acm_read_bulk+0x51/0xbf [cdc_acm] [<c058189f>] usb_hcd_giveback_urb+0x2d/0x5d [<f082865c>] uhci_giveback_urb+0x104/0x12b [uhci_hcd] [<f0828c79>] uhci_scan_schedule+0x4fc/0x77b [uhci_hcd] [<f082a6ed>] uhci_irq+0x129/0x13f [uhci_hcd] [<c05823f3>] usb_hcd_irq+0x23/0x50 [<c044dcee>] handle_IRQ_event+0x23/0x49 [<c044ddaa>] __do_IRQ+0x96/0xf2 [<c04068bf>] do_IRQ+0x9e/0xbc ======================= -- Additional comment from rhentosh on 2007-01-09 22:45 EST -- Created an attachment (id=145220) Full serial capture of failed system -- Additional comment from zaitcev on 2007-03-01 20:50 EST -- Robert, I'm convinced that the failure is fixed in updated kernels for FC-6. I have verified the 2.6.20-1.2923.fc6, and the change is plainly there. Please re-test with an updated kernel and close the bug if the problem is gone. The 2.6.20 has this versus the 2.6.18: next_buffer: - spin_lock(&acm->read_lock); + spin_lock_irqsave(&acm->read_lock, flags); if (list_empty(&acm->filled_read_bufs)) { - spin_unlock(&acm->read_lock); + spin_unlock_irqrestore(&acm->read_lock, flags); goto urbs; } -- Additional comment from zaitcev on 2007-03-01 20:52 EST -- Oooh, wait. I see what the problem is. The RHEL 5 has this problem, because it ships with 2.6.18. It's just the Bugzilla has product version set to fc6. -- Additional comment from zaitcev on 2007-03-01 20:58 EST -- Created an attachment (id=149082) Candidate patch #1 (RHEL 5) This is a small backport from Fedora, which should be sufficient. -- Additional comment from zaitcev on 2007-03-08 20:51 EST -- I have verified that the fix is in 2.6.19-1.2911.6.4.fc6. Robert, please verify that it works and close the bug. -- Additional comment from rhentosh on 2007-04-20 09:33 EST -- I have also verified that the patch works on FC5 2.6.18-1.2239 and RHEL5 2.6.18-15.el5. Both patch cleanly. Both were tested heavily for a day. Would have expected around 8-10 failures in that time. Patch works.
This request was evaluated by Red Hat Product Management for inclusion, but this component is not scheduled to be updated in the current Red Hat Enterprise Linux release. If you would like this request to be reviewed for the next minor release, ask your support representative to set the next rhel-x.y flag to "?".
This Bugzilla has been reviewed by Red Hat and is not planned on being addressed in Red Hat Enterprise Linux 5, and therefore is being closed. If this bug is critical to production systems, please contact your Red Hat support representative and provide a sufficient business justification in order to re-open it.