[Pkg-alsa-devel] Bug#386822: alsa-driver locks up machine when wine probes for MIDI device

[Oliver Freyd]

Package: alsa-source
Version: 1.0.11-5

When i invoke wineprefixcreate (from the wine package), after a short
time the machine locks up completely. If I invoke it from the linux console
without X, I see an error message relating to a source file from alsa,
mpu401_uart.c, after that it locks up.

I have a trident soundcard in this machine, a 4DWAVE-NX I think.

On www.alsa-project.org they have version 1.0.12 out, and exactly this bug
is reported as "fixed" in the changelog. 
They say it happens because the mpu401 device can be opened even if it 
doesn't exist/ is faulty, so later it locks up the machine.  

So I diffed mpu401_uart.c
from 1.0.12 against the one from debian and created a patch, and
wine runs without locking up my machine.

I suppose this bug will happen only on machines with certain soundcards
installed, if they use the snd-mpu401-uart module.

I am using debian testing (etch) kernel 2.4.27

  

 
-------------- next part --------------
--- mpu401_uart_old.c	2005-11-18 19:52:14.000000000 +0100
+++ mpu401_uart.c	2006-09-08 20:50:50.000000000 +0200
@@ -183,7 +183,8 @@
 
  */
 
-static void snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd, int ack)
+static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd,
+			       int ack)
 {
 	unsigned long flags;
 	int timeout, ok;
@@ -215,12 +216,17 @@
 		if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
 			ok = 1;
 	} else {
-		ok = 1;
+	  ok = 1;
 	}
 	spin_unlock_irqrestore(&mpu->input_lock, flags);
-	if (! ok)
-		snd_printk("cmd: 0x%x failed at 0x%lx (status = 0x%x, data = 0x%x)\n", cmd, mpu->port, mpu->read(mpu, MPU401C(mpu)), mpu->read(mpu, MPU401D(mpu)));
-	// snd_printk("cmd: 0x%x at 0x%lx (status = 0x%x, data = 0x%x)\n", cmd, mpu->port, mpu->read(mpu, MPU401C(mpu)), mpu->read(mpu, MPU401D(mpu)));
+	if (!ok) {
+		snd_printk(KERN_ERR "cmd: 0x%x failed at 0x%lx "
+			   "(status = 0x%x, data = 0x%x)\n", cmd, mpu->port,
+			   mpu->read(mpu, MPU401C(mpu)),
+			   mpu->read(mpu, MPU401D(mpu)));
+		return 1;
+	}
+	return 0;
 }
 
 /*
@@ -235,12 +241,19 @@
 	if (mpu->open_input && (err = mpu->open_input(mpu)) < 0)
 		return err;
 	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
-		snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1);
-		snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1);
+		if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
+			goto error_out;
+		if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1))
+			goto error_out;
 	}
 	mpu->substream_input = substream;
 	set_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
 	return 0;
+
+error_out:
+	if (mpu->open_input && mpu->close_input)
+		mpu->close_input(mpu);
+	return -EIO;
 }
 
 static int snd_mpu401_uart_output_open(struct snd_rawmidi_substream *substream)
@@ -252,39 +265,52 @@
 	if (mpu->open_output && (err = mpu->open_output(mpu)) < 0)
 		return err;
 	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
-		snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1);
-		snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1);
+		if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
+			goto error_out;
+		if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1))
+			goto error_out;
 	}
 	mpu->substream_output = substream;
 	set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
 	return 0;
+
+error_out:
+	if (mpu->open_output && mpu->close_output)
+		mpu->close_output(mpu);
+	return -EIO;
 }
 
 static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream)
 {
 	struct snd_mpu401 *mpu;
+	int err = 0;
 
 	mpu = substream->rmidi->private_data;
 	clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
 	mpu->substream_input = NULL;
 	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
-		snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
+		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
 	if (mpu->close_input)
 		mpu->close_input(mpu);
+	if (err)
+		return -EIO;
 	return 0;
 }
 
 static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream)
 {
 	struct snd_mpu401 *mpu;
+	int err = 0;
 
 	mpu = substream->rmidi->private_data;
 	clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
 	mpu->substream_output = NULL;
 	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
-		snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
+		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
 	if (mpu->close_output)
 		mpu->close_output(mpu);
+	if (err)
+		return -EIO;
 	return 0;
 }