From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.8) Gecko/20050513 Fedora/1.0.4-1.3.1 Firefox/1.0.4 Description of problem: When connecting a Kensington USB webcam, the kernel complains about a missing release callback in the driver. But, what is worse, when actually using it, it seems the driver calls a function which may sleep from interrupt context. The camera does seem to work though. Version-Release number of selected component (if applicable): kernel-2.6.11-1.27_FC3 How reproducible: Always Steps to Reproduce: 1. Plug in webcam 2. Start gnomemeeting (for instance) Actual Results: Lots of entries in the kernel log file. Expected Results: No entries in the kernel log file. Additional info: This is the message in the log after plugging the camera in: drivers/usb/media/se401.c: SE401 usb camera driver version 0.24 registering videodev: "Kensington VideoCAM 67016" has no release callback. Please fix your driver for proper sysfs support, see http://lwn.net/Articles/36850/ And this is the message that keeps being logged when the camera is in use: Debug: sleeping function called from invalid context at mm/slab.c:2088 in_atomic():1, irqs_disabled():1 [<c011bfbe>] __might_sleep+0x9c/0xa4 [<c0154e85>] __kmalloc+0x7c/0x7e [<e098565d>] ohci_urb_enqueue+0x81/0x5be [ohci_hcd] [<c0119da0>] activate_task+0x56/0x65 [<c02bf741>] hcd_submit_urb+0x1b5/0x304 [<c011ab09>] __wake_up_common+0x35/0x55 [<c02c059a>] usb_submit_urb+0x1bd/0x2bb [<e0adc5c5>] se401_video_irq+0x7d/0x1ff [se401] [<c02c0110>] usb_hcd_giveback_urb+0x17/0x49 [<e0984175>] finish_urb+0xc6/0x2c2 [ohci_hcd] [<e09854d9>] finish_unlinks+0x245/0x284 [ohci_hcd] [<e09855cb>] dl_done_list+0xb3/0xc4 [ohci_hcd] [<e09868cb>] ohci_irq+0xed/0x361 [ohci_hcd] [<c010878f>] timer_interrupt+0x80/0x22e [<c02c0166>] usb_hcd_irq+0x24/0x57 [<c0148640>] handle_IRQ_event+0x31/0x62 [<c014872f>] __do_IRQ+0xbe/0x31f [<c010564f>] do_IRQ+0x4c/0x85 ======================= [<c0103a72>] common_interrupt+0x1a/0x20
An update has been released for Fedora Core 3 (kernel-2.6.12-1.1372_FC3) which may contain a fix for your problem. Please update to this new kernel, and report whether or not it fixes your problem. If you have updated to Fedora Core 4 since this bug was opened, and the problem still occurs with the latest updates for that release, please change the version field of this bug to 'fc4'. Thank you.
Sorry, I no longer run Fedora, so I can't test this anymore. However, with Debian (running kernel 2.6.8-2-k7) the "release callback" warning is present there too, but not the other "sleeping function called from invalid context at mm/slab.c:2088" warning.