On Mon, Feb 2, 2009 at 9:43 AM, Dave Young <hidave.darkstar@xxxxxxxxx> wrote: > On Sun, Feb 1, 2009 at 11:51 PM, Greg KH <greg@xxxxxxxxx> wrote: >> On Sun, Feb 01, 2009 at 06:53:23PM +0800, Dave Young wrote: >>> >>> In case with "nousb" booting, serial drivers will trigger kernel oops. >> >> They will? What is the oops message? > > Yes, they will, at lease I saw usb_serial/aircable/ftdi_sio oops. I > will manage to copy the oops message later. I can not copy the oops message, so I just hand copy something here: BUG: unable to handle kernel NULL pointer dereference at 00000001 IP: [<c0527636>] kset_find_obj+0x3b/0x5c *pde = 00000000 Oops: 0000 [#1] SMP [snip...] EIP is at kset_find_obj+0x3b/0x5c EAX:00000001 [snip...] Call Trace: driver_register destruct_tty_driver usb_serial_bus_register usb_serial_register aircable_init _stext aircable_init restore_nocheck_notrace pci_arch_init [snip...] Actually, after the usb_serial_init failed, the usb_serial_bus_type will be unregistered. So when serial dirvers call usb_serial_register (then usb_serial_bus_register, and then driver_register), due to the bus kset already unregistered kernel will oops. > >> >>> Here add usb_disabled() check in usb_serial_init and usb_serial_register >> >> This is odd, is it something new? Why is usb-serial the only driver >> that needs such a thing? > > No, it is not new thing. usb serial drivers normally call > usb_serial_register first, then usb_register, usb_register will fail > due to "nousb" checking, but usb_serial_register no. > >> >> confused, >> >> greg k-h >> > > > > -- > Regards > dave > -- Regards dave -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
