CVS commit: src/sys/dev/usb

["matthew green" <mrg%netbsd.org@localhost>]

Module Name:    src
Committed By:   mrg
Date:           Sat Apr 27 01:23:26 UTC 2019

Modified Files:
        src/sys/dev/usb: uchcom.c

Log Message:
fix uchcom(4) detach, like umodem(4) recently:

- use static normally in umodem_common.c
- add sc_refcnt, sc_lock and sc_detach_cv to softc.  usage is:
  - sc_dying is protected by sc_lock
  - sc_detach_cv is matched with sc_lock for cv operations
  - sc_refcnt is increased in open and decreased in close, any time
    it is decreased, it is checked for less than zero, and a broadcast
    performed on sc_detach_cv.  detach waits for sc_refcnt
- uchcom_param() and uchcom_set() check for sc_dying

this fixes pullout out an open ucom@uchcom.

XXX: pullup


To generate a diff of this commit:
cvs rdiff -u -r1.28 -r1.29 src/sys/dev/usb/uchcom.c

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