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    SubjectRe: WARNINGs in usb-serial.c
    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

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      Last update: 2009-09-07 17:11    [W:0.020 / U:74.260 seconds]
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