[src/nick-nhusb]: src/sys/dev/usb sc_intr_lock is protecting against usb call...

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

details:   https://anonhg.NetBSD.org/src/rev/fc7ac22eeeb2
branches:  nick-nhusb
changeset: 334447:fc7ac22eeeb2
user:      skrll <skrll%NetBSD.org@localhost>
date:      Wed Mar 23 22:11:20 2016 +0000

description:
sc_intr_lock is protecting against usb callbacks so can be IPL_SOFTUSB

diffstat:

 sys/dev/usb/uaudio.c |  48 +++++++++++++++++++++---------------------------
 1 files changed, 21 insertions(+), 27 deletions(-)

diffs (183 lines):

diff -r 616fffed6dfd -r fc7ac22eeeb2 sys/dev/usb/uaudio.c
--- a/sys/dev/usb/uaudio.c      Wed Mar 23 22:04:18 2016 +0000
+++ b/sys/dev/usb/uaudio.c      Wed Mar 23 22:11:20 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uaudio.c,v 1.140.2.14 2016/03/23 22:04:18 skrll Exp $  */
+/*     $NetBSD: uaudio.c,v 1.140.2.15 2016/03/23 22:11:20 skrll Exp $  */
 
 /*
  * Copyright (c) 1999, 2012 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uaudio.c,v 1.140.2.14 2016/03/23 22:04:18 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uaudio.c,v 1.140.2.15 2016/03/23 22:11:20 skrll Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -177,12 +177,8 @@
 };
 
 /*
- * XXX Locking notes:
- *
- *    The MI USB audio subsystem is not MP-SAFE.  Our strategy here
- *    is to ensure we have the kernel lock held when calling into
- *    usbd, and, generally, to have dropped the sc_intr_lock during
- *    these sections as well since the usb code will sleep.
+ *    The MI USB audio subsystem is now MP-SAFE and expects sc_intr_lock to be
+ *    held on entry the callbacks passed to uaudio_trigger_{in,out}put
  */
 struct uaudio_softc {
        device_t        sc_dev;         /* base device */
@@ -431,7 +427,7 @@
        sc->sc_dev = self;
        sc->sc_udev = uiaa->uiaa_device;
        mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE);
-       mutex_init(&sc->sc_intr_lock, MUTEX_DEFAULT, IPL_SCHED);
+       mutex_init(&sc->sc_intr_lock, MUTEX_DEFAULT, IPL_SOFTUSB);
 
        strlcpy(sc->sc_adev.name, "USB audio", sizeof(sc->sc_adev.name));
        strlcpy(sc->sc_adev.version, "", sizeof(sc->sc_adev.version));
@@ -2237,14 +2233,14 @@
 
        DPRINTF("%s", "enter\n");
 
-       mutex_spin_exit(&sc->sc_intr_lock);
+       mutex_exit(&sc->sc_intr_lock);
        if (sc->sc_playchan.pipe != NULL) {
                uaudio_chan_abort(sc, &sc->sc_playchan);
                uaudio_chan_free_buffers(sc, &sc->sc_playchan);
                uaudio_chan_close(sc, &sc->sc_playchan);
                sc->sc_playchan.intr = NULL;
        }
-       mutex_spin_enter(&sc->sc_intr_lock);
+       mutex_enter(&sc->sc_intr_lock);
 
        return 0;
 }
@@ -2256,14 +2252,14 @@
 
        DPRINTF("%s", "enter\n");
 
-       mutex_spin_exit(&sc->sc_intr_lock);
+       mutex_exit(&sc->sc_intr_lock);
        if (sc->sc_recchan.pipe != NULL) {
                uaudio_chan_abort(sc, &sc->sc_recchan);
                uaudio_chan_free_buffers(sc, &sc->sc_recchan);
                uaudio_chan_close(sc, &sc->sc_recchan);
                sc->sc_recchan.intr = NULL;
        }
-       mutex_spin_enter(&sc->sc_intr_lock);
+       mutex_enter(&sc->sc_intr_lock);
 
        return 0;
 }
@@ -2605,17 +2601,17 @@
                    "fraction=0.%03d\n", ch->sample_size, ch->bytes_per_frame,
                    ch->fraction);
 
-       mutex_spin_exit(&sc->sc_intr_lock);
+       mutex_exit(&sc->sc_intr_lock);
        err = uaudio_chan_open(sc, ch);
        if (err) {
-               mutex_spin_enter(&sc->sc_intr_lock);
+               mutex_enter(&sc->sc_intr_lock);
                return EIO;
        }
 
        err = uaudio_chan_alloc_buffers(sc, ch);
        if (err) {
                uaudio_chan_close(sc, ch);
-               mutex_spin_enter(&sc->sc_intr_lock);
+               mutex_enter(&sc->sc_intr_lock);
                return EIO;
        }
 
@@ -2628,7 +2624,7 @@
                uaudio_chan_rtransfer(ch);
        }
 
-       mutex_spin_enter(&sc->sc_intr_lock);
+       mutex_enter(&sc->sc_intr_lock);
 
        return 0;
 }
@@ -2655,17 +2651,17 @@
                    "fraction=0.%03d\n", ch->sample_size, ch->bytes_per_frame,
                    ch->fraction);
 
-       mutex_spin_exit(&sc->sc_intr_lock);
+       mutex_exit(&sc->sc_intr_lock);
        err = uaudio_chan_open(sc, ch);
        if (err) {
-               mutex_spin_enter(&sc->sc_intr_lock);
+               mutex_enter(&sc->sc_intr_lock);
                return EIO;
        }
 
        err = uaudio_chan_alloc_buffers(sc, ch);
        if (err) {
                uaudio_chan_close(sc, ch);
-               mutex_spin_enter(&sc->sc_intr_lock);
+               mutex_enter(&sc->sc_intr_lock);
                return EIO;
        }
 
@@ -2674,7 +2670,7 @@
 
        for (i = 0; i < UAUDIO_NCHANBUFS-1; i++) /* XXX */
                uaudio_chan_ptransfer(ch);
-       mutex_spin_enter(&sc->sc_intr_lock);
+       mutex_enter(&sc->sc_intr_lock);
 
        return 0;
 }
@@ -2798,7 +2794,6 @@
                usbd_destroy_xfer(ch->chanbufs[i].xfer);
 }
 
-/* Called with USB lock held. */
 Static void
 uaudio_chan_ptransfer(struct chan *ch)
 {
@@ -2887,20 +2882,19 @@
 #endif
 
        ch->transferred += cb->size;
-       mutex_spin_enter(&ch->sc->sc_intr_lock);
+       mutex_enter(&ch->sc->sc_intr_lock);
        /* Call back to upper layer */
        while (ch->transferred >= ch->blksize) {
                ch->transferred -= ch->blksize;
                DPRINTFN(5, "call %p(%p)\n", ch->intr, ch->arg);
                ch->intr(ch->arg);
        }
-       mutex_spin_exit(&ch->sc->sc_intr_lock);
+       mutex_exit(&ch->sc->sc_intr_lock);
 
        /* start next transfer */
        uaudio_chan_ptransfer(ch);
 }
 
-/* Called with USB lock held. */
 Static void
 uaudio_chan_rtransfer(struct chan *ch)
 {
@@ -2990,13 +2984,13 @@
 
        /* Call back to upper layer */
        ch->transferred += count;
-       mutex_spin_enter(&ch->sc->sc_intr_lock);
+       mutex_enter(&ch->sc->sc_intr_lock);
        while (ch->transferred >= ch->blksize) {
                ch->transferred -= ch->blksize;
                DPRINTFN(5, "call %p(%p)\n", ch->intr, ch->arg);
                ch->intr(ch->arg);
        }
-       mutex_spin_exit(&ch->sc->sc_intr_lock);
+       mutex_exit(&ch->sc->sc_intr_lock);
 
        /* start next transfer */
        uaudio_chan_rtransfer(ch);