Bob Copeland wrote:
On 3/12/06, Paul Fulghum <[EMAIL PROTECTED]> wrote:--- linux-2.6.16-rc5/drivers/usb/class/cdc-acm.c 2006-02-27 09:24:29.000000000 -0600 +++ b/drivers/usb/class/cdc-acm.c 2006-03-12 10:22:21.000000000 -0600 @@ -980,7 +980,7 @@ skip_normal_probe: usb_driver_claim_interface(&acm_driver, data_interface, acm); usb_get_intf(control_interface); - tty_register_device(acm_tty_driver, minor, &control_interface->dev); + tty_register_device(acm_tty_driver, minor, NULL); acm_table[minor] = acm; usb_set_intfdata (intf, acm);Paul, No oops with the above patch. thanks! -Bob
I think what is happening is that control_interface->dev is used to back 2 sysfs entries (one usb, and one tty). When the usb device is disconnected, the usb sysfs entries are removed and the backing device is released. But the tty sysfs entry is not removed until later after the tty is closed. This removal oops because the backing device (or some sysfs entity associated with the backing device) has already been freed. The slab poisoning is needed to catch this. That's my theory, but I'm no expert on USB or sysfs. The above change does not associate the device with the tty object, and no tty sysfs entry is made that references the device. No function is lost, but some info is not exported to userland. I guess a more thorough approach would be to somehow not release the usb device until the tty close completes. But that sounds kind of messy, as the usb code would need to know about any other class sysfs entries besides usb. (tty, maybe storage, etc) Greg or the USB folks are more qualified to decide the details. Thanks for your help Bob. -- Paul ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
