CVS commit: [netbsd-10] src/sys/kern

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

Module Name:    src
Committed By:   martin
Date:           Tue Feb 14 16:16:30 UTC 2023

Modified Files:
        src/sys/kern [netbsd-10]: subr_devsw.c

Log Message:
Pull up following revision(s) (requested by buhrow in ticket #84):

        sys/kern/subr_devsw.c: revision 1.50

        When a device driver calls devsw_attach() it has the option of attaching a block device
structure and a character device structure, or, just the character device structure.
With the existing code, if a driver elects not to attach a block device structure and if it
asks for a major number to be dynamically assigned to its character interface,
that driver will not be able to detach and reattach its character driver interface.  This is a very
long standing bug which didn't come to light until we began using loadable kernel modules more
heavily.  this patch fixes this problem.  With this patch in place, drivers that implement only
a character device interface may detach and reattach that character interface as often as they
need to.

Fixes PR kern/57229


To generate a diff of this commit:
cvs rdiff -u -r1.49 -r1.49.2.1 src/sys/kern/subr_devsw.c

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