[src/trunk]: src/sys/dev/pad Don't hold the thread_lock between successive ca...

[nat <nat%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f4b7579e7598
branches:  trunk
changeset: 821152:f4b7579e7598
user:      nat <nat%NetBSD.org@localhost>
date:      Thu Jan 26 04:10:27 2017 +0000

description:
Don't hold the thread_lock between successive calls to sc_intr as it
breaks mixing.

This will help passing the atf test.  Changes to audio.c to ensue this
will be in a followup commit.

diffstat:

 sys/dev/pad/pad.c |  22 +++++++++++-----------
 1 files changed, 11 insertions(+), 11 deletions(-)

diffs (64 lines):

diff -r 47653c925148 -r f4b7579e7598 sys/dev/pad/pad.c
--- a/sys/dev/pad/pad.c Thu Jan 26 03:54:54 2017 +0000
+++ b/sys/dev/pad/pad.c Thu Jan 26 04:10:27 2017 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pad.c,v 1.26 2016/10/15 07:08:06 nat Exp $ */
+/* $NetBSD: pad.c,v 1.27 2017/01/26 04:10:27 nat Exp $ */
 
 /*-
  * Copyright (c) 2007 Jared D. McNeill <jmcneill%invisible.ca@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pad.c,v 1.26 2016/10/15 07:08:06 nat Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pad.c,v 1.27 2017/01/26 04:10:27 nat Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -362,11 +362,11 @@
 
        err = 0;
 
-       mutex_enter(&sc->sc_lock);
-       intr = sc->sc_intr;
-       intrarg = sc->sc_intrarg;
+       while (uio->uio_resid > 0 && !err) {
+               mutex_enter(&sc->sc_lock);
+               intr = sc->sc_intr;
+               intrarg = sc->sc_intrarg;
 
-       while (uio->uio_resid > 0 && !err) {
                getmicrotime(&now);
                nowusec = (now.tv_sec * 1000000) + now.tv_usec;
                lastusec = (sc->sc_last.tv_sec * 1000000) +
@@ -394,7 +394,6 @@
 
                        mutex_exit(&sc->sc_lock);
                        err = uiomove(pb.pb_ptr, pb.pb_len, uio);
-                       mutex_enter(&sc->sc_lock);
                        continue;
                }
 
@@ -407,16 +406,17 @@
                        intr = sc->sc_intr;
                        intrarg = sc->sc_intrarg;
                        err = 0;
+                       mutex_exit(&sc->sc_lock);
                        continue;
                }
                err = cv_wait_sig(&sc->sc_condvar, &sc->sc_lock);
-               if (err != 0)
+               if (err != 0) {
+                       mutex_exit(&sc->sc_lock);
                        break;
+               }
 
-               intr = sc->sc_intr;
-               intrarg = sc->sc_intrarg;
+               mutex_exit(&sc->sc_lock);
        }
-       mutex_exit(&sc->sc_lock);
 
        return err;
 }