CVS commit: [netbsd-9] src/sys/dev/usb

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Sat Nov 29 17:01:47 UTC 2025

Modified Files:
        src/sys/dev/usb [netbsd-9]: ucom.c

Log Message:
Pull up following revision(s) (requested by skrll in ticket #1983):

        sys/dev/usb/ucom.c: revision 1.142
        sys/dev/usb/ucom.c: revision 1.149

Fix ucom input queue corruption on open-after-close

When closing ucom(4) while a transfer was in progress, ucomreadcb()
is called with USBD_CANCELLED. Previously, the ucom_buffer was not
removed from sc->sc_ibuff_empty, leading to queue corruption when
reopening the device: ucomopen() calls ucomsubmitread(), which
queues the ucom_buffer again.

We fix this by making sure the ucom_buffer is removed from queue
on USBD_CANCELLED or USBD_IOERROR.

Approved by Nick Hudson, who rewrote the comment.

Add a KASSERT in ucomreadcb that the ucom_buffer removed from the
sc_ibuff_empty list is associated with the current xfer. This was
suggested by Taylor.

While I'm here fix a typo in the comment above this code.


To generate a diff of this commit:
cvs rdiff -u -r1.125.2.2 -r1.125.2.3 src/sys/dev/usb/ucom.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.