CVS commit: src/sys/dev/usb

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

Module Name:    src
Committed By:   mrg
Date:           Mon May  6 23:47:39 UTC 2019

Modified Files:
        src/sys/dev/usb: umodem_common.c umodemvar.h

Log Message:
revert most of:

>fix umodem(4) detach:
>
>- ucom(4) needs kpreempt disabled around softint_schedule()
>- switch a copied printf() to aprint_error_dev()
>- use static normally in umodem_common.c
>- remove unused sc_openings in softc, convert sc_dying to real bool
>- 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.
>- umodem_param() and umodem_set() check for sc_dying
>
>this fixes pullout out an open ucom@umodem.
>
>@skrll.
>
>XXX: pullup

it only fixes the issue by chance (slightly delays, which
allows task to run, but there is no guarantee.  real fix
is incoming for all ucom parents.


To generate a diff of this commit:
cvs rdiff -u -r1.28 -r1.29 src/sys/dev/usb/umodem_common.c
cvs rdiff -u -r1.10 -r1.11 src/sys/dev/usb/umodemvar.h

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