On Mon, 7 Sep 2009, Miklos Szeredi wrote: > Here's a reproducible Oops on that kernel when trying to connect with > wvdial. This is a regression compared to -linus, where wvdial works > (most of the time anyway). > > I can bisect it if it's not immediately obvious what is happening... I don't think bisecting will help (or is even possible). > BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 > IP: [<ffffffffa020709c>] serial_chars_in_buffer+0x47/0x5f [usbserial] It's difficult to say without an assembly listing, but I gather that serial_chars_in_buffer() is seeing port->serial == NULL. Can you verify this? This is unexpected, because port->serial is initialized in usb_serial_probe() and is not set to NULL until destroy_serial(), after which port should not be used at all. Can you add a #define DEBUG line at the start of usb-serial.c (before the #include lines) so that we can tell if destroy_serial() is getting called too early? When you do, post the dmesg log showing everything from the time you start running your test. Alan Stern -- 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
