CVS commit: src/sys/dev/usb

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Tue Sep  7 10:43:34 UTC 2021

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

Log Message:
ugen(4): Use cv_broadcast to wake all I/O operations on detach.

Nothing prevents two concurrent reads or two concurrent writes on any
particular ugen endpoint, as far as I can tell, and we need to wake
all of them, so use cv_broadcast rather than cv_signal on detach.

XXX It's not clear to me that cv_signal in the xfer completion
callbacks is correct either: any one consumer might use less than the
full buffer.  So I think either we should use cv_broadcast, or
consumers that don't use the whole buffer need to issue cv_signal too
to wake up another consumer even if we want to avoid a thundering
herd.


To generate a diff of this commit:
cvs rdiff -u -r1.164 -r1.165 src/sys/dev/usb/ugen.c

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