Fix the spl handling. There's still the effect that the timers have

sometimes already been released at the time pcaclose() is called, but
this is now prevented from deadlocking by checking for a running timer
at the start of pca_wait().

At least, i can now play xboing again with pcaudio, this used to hang
the entire system previously within a few seconds.

1 files changed, 32 insertions, 14 deletions

diff --git a/sys/i386/isa/pcaudio.c b/sys/i386/isa/pcaudio.c
index 5ede8f0..6b31817 100644
--- a/sys/i386/isa/pcaudio.c
+++ b/sys/i386/isa/pcaudio.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *	$Id: pcaudio.c,v 1.26 1995/12/22 15:27:48 bde Exp $
+ *	$Id: pcaudio.c,v 1.27 1996/03/28 14:28:47 scrappy Exp $
  */
 
 #include "pca.h"
@@ -166,6 +166,9 @@ pca_init()
 static int
 pca_start(void)
 {
+	int x = splhigh();
+	int rv = 0;
+
 	/* use the first buffer */
 	pca_status.current  = 0;
 	pca_status.index = 0;
@@ -173,21 +176,24 @@ pca_start(void)
         pca_status.buffer  = pca_status.buf[pca_status.current];
         pca_status.oldval = inb(IO_PPI) | 0x03;
         /* acquire the timers */
-	if (acquire_timer2(TIMER_LSB|TIMER_ONESHOT)) {
-		return -1;
-	}
-	if (acquire_timer0(INTERRUPT_RATE, pcaintr)) {
+	if (acquire_timer2(TIMER_LSB|TIMER_ONESHOT))
+		rv = -1;
+	else if (acquire_timer0(INTERRUPT_RATE, pcaintr)) {
 		release_timer2();
-		return -1;
-	}
-	pca_status.timer_on = 1;
-	return 0;
+		rv =  -1;
+	} else
+		pca_status.timer_on = 1;
+
+	splx(x);
+	return rv;
 }
 
 
 static void
 pca_stop(void)
 {
+	int x = splhigh();
+
 	/* release the timers */
 	release_timer0();
 	release_timer2();
@@ -198,37 +204,49 @@ pca_stop(void)
 	pca_status.current = 0;
 	pca_status.buffer = pca_status.buf[pca_status.current];
 	pca_status.timer_on = 0;
+	splx(x);
 }
 
 
 static void
 pca_pause()
 {
+	int x = splhigh();
+
 	release_timer0();
 	release_timer2();
 	pca_status.timer_on = 0;
+	splx(x);
 }
 
 
 static void
 pca_continue()
 {
+	int x = splhigh();
+
         pca_status.oldval = inb(IO_PPI) | 0x03;
 	acquire_timer2(TIMER_LSB|TIMER_ONESHOT);
 	acquire_timer0(INTERRUPT_RATE, pcaintr);
 	pca_status.timer_on = 1;
+	splx(x);
 }
 
 
 static int
 pca_wait(void)
 {
-	int error;
+	int error, x;
+
+	if (!pca_status.timer_on)
+		return 0;
 
 	while (pca_status.in_use[0] || pca_status.in_use[1]) {
+		x = spltty();
 		pca_sleep = 1;
 		error = tsleep(&pca_sleep, PZERO|PCATCH, "pca_drain", 0);
 		pca_sleep = 0;
+		splx(x);
 		if (error != 0 && error != ERESTART) {
 			pca_stop();
 			return error;
@@ -332,7 +350,7 @@ pcaclose(dev_t dev, int flags, int fmt, struct proc *p)
 static	int
 pcawrite(dev_t dev, struct uio *uio, int flag)
 {
-	int count, error, which;
+	int count, error, which, x;
 
 	/* only audio device can be written */
 	if (minor(dev) > 0)
@@ -340,9 +358,11 @@ pcawrite(dev_t dev, struct uio *uio, int flag)
 
 	while ((count = min(BUF_SIZE, uio->uio_resid)) > 0) {
 		if (pca_status.in_use[0] && pca_status.in_use[1]) {
+			x = spltty();
 			pca_sleep = 1;
 			error = tsleep(&pca_sleep, PZERO|PCATCH, "pca_wait", 0);
 			pca_sleep = 0;
+			splx(x);
 			if (error != 0 && error != ERESTART) {
 				pca_stop();
 				return error;
@@ -457,10 +477,8 @@ pcaintr(struct clockframe *frame)
 		pca_status.in_use[pca_status.current] = 0;
 		pca_status.current ^= 1;
 		pca_status.buffer = pca_status.buf[pca_status.current];
-                if (pca_sleep) {
+                if (pca_sleep)
 			wakeup(&pca_sleep);
-			pca_sleep = 0;
-		}
 		if (pca_status.wsel.si_pid) {
 			selwakeup((struct selinfo *)&pca_status.wsel.si_pid);
 			pca_status.wsel.si_pid = 0;