[Ubuntu PATCH] FIx no mpu401 interface can cause hard freeze

[Ubuntu PATCH] FIx no mpu401 interface can cause hard freeze

[Randy Dunlap]

This patch fixes the remaining instances in our tree where a non-
existent mpu401 interface can cause a hard freeze when i/o is issued.

This commit closes Malone #34831.

Bug: https://launchpad.net/distros/ubuntu/+source/linux-source-2.6.15/+bug/34831

patch location:
http://www.kernel.org/git/?p=linux/kernel/git/bcollins/ubuntu-dapper.git;a=commitdiff;h=b422309cdd980cfefe99379796c04e961d3c1544

---
 sound/pci/emu10k1/emu10k1x.c  |   35 +++++++++++++++++++++++++----------
 sound/pci/emu10k1/emumpu401.c |   35 +++++++++++++++++++++++++----------
 2 files changed, 50 insertions(+), 20 deletions(-)

--- linux-2617-g21.orig/sound/pci/emu10k1/emu10k1x.c
+++ linux-2617-g21/sound/pci/emu10k1/emu10k1x.c
@@ -1286,7 +1286,7 @@ static void snd_emu10k1x_midi_interrupt(
 	do_emu10k1x_midi_interrupt(emu, &emu->midi, status);
 }
 
-static void snd_emu10k1x_midi_cmd(struct emu10k1x * emu,
+static int snd_emu10k1x_midi_cmd(struct emu10k1x * emu,
 				  struct emu10k1x_midi *midi, unsigned char cmd, int ack)
 {
 	unsigned long flags;
@@ -1312,11 +1312,14 @@ static void snd_emu10k1x_midi_cmd(struct
 		ok = 1;
 	}
 	spin_unlock_irqrestore(&midi->input_lock, flags);
-	if (!ok)
+	if (!ok) {
 		snd_printk(KERN_ERR "midi_cmd: 0x%x failed at 0x%lx (status = 0x%x, data = 0x%x)!!!\n",
 			   cmd, emu->port,
 			   mpu401_read_stat(emu, midi),
 			   mpu401_read_data(emu, midi));
+		return 1;
+	}
+	return 0;
 }
 
 static int snd_emu10k1x_midi_input_open(struct snd_rawmidi_substream *substream)
@@ -1332,12 +1335,17 @@ static int snd_emu10k1x_midi_input_open(
 	midi->substream_input = substream;
 	if (!(midi->midi_mode & EMU10K1X_MIDI_MODE_OUTPUT)) {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
-		snd_emu10k1x_midi_cmd(emu, midi, MPU401_RESET, 1);
-		snd_emu10k1x_midi_cmd(emu, midi, MPU401_ENTER_UART, 1);
+		if (snd_emu10k1x_midi_cmd(emu, midi, MPU401_RESET, 1))
+			goto error_out;
+		if (snd_emu10k1x_midi_cmd(emu, midi, MPU401_ENTER_UART, 1))
+			goto error_out;
 	} else {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
 	}
 	return 0;
+
+error_out:
+	return -EIO;
 }
 
 static int snd_emu10k1x_midi_output_open(struct snd_rawmidi_substream *substream)
@@ -1353,12 +1361,17 @@ static int snd_emu10k1x_midi_output_open
 	midi->substream_output = substream;
 	if (!(midi->midi_mode & EMU10K1X_MIDI_MODE_INPUT)) {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
-		snd_emu10k1x_midi_cmd(emu, midi, MPU401_RESET, 1);
-		snd_emu10k1x_midi_cmd(emu, midi, MPU401_ENTER_UART, 1);
+		if (snd_emu10k1x_midi_cmd(emu, midi, MPU401_RESET, 1))
+			goto error_out;
+		if (snd_emu10k1x_midi_cmd(emu, midi, MPU401_ENTER_UART, 1))
+			goto error_out;
 	} else {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
 	}
 	return 0;
+
+error_out:
+	return -EIO;
 }
 
 static int snd_emu10k1x_midi_input_close(struct snd_rawmidi_substream *substream)
@@ -1366,6 +1379,7 @@ static int snd_emu10k1x_midi_input_close
 	struct emu10k1x *emu;
 	struct emu10k1x_midi *midi = substream->rmidi->private_data;
 	unsigned long flags;
+	int err = 0;
 
 	emu = midi->emu;
 	snd_assert(emu, return -ENXIO);
@@ -1375,11 +1389,11 @@ static int snd_emu10k1x_midi_input_close
 	midi->substream_input = NULL;
 	if (!(midi->midi_mode & EMU10K1X_MIDI_MODE_OUTPUT)) {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
-		snd_emu10k1x_midi_cmd(emu, midi, MPU401_RESET, 0);
+		err = snd_emu10k1x_midi_cmd(emu, midi, MPU401_RESET, 0);
 	} else {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
 	}
-	return 0;
+	return err;
 }
 
 static int snd_emu10k1x_midi_output_close(struct snd_rawmidi_substream *substream)
@@ -1387,6 +1401,7 @@ static int snd_emu10k1x_midi_output_clos
 	struct emu10k1x *emu;
 	struct emu10k1x_midi *midi = substream->rmidi->private_data;
 	unsigned long flags;
+	int err = 0;
 
 	emu = midi->emu;
 	snd_assert(emu, return -ENXIO);
@@ -1396,11 +1411,11 @@ static int snd_emu10k1x_midi_output_clos
 	midi->substream_output = NULL;
 	if (!(midi->midi_mode & EMU10K1X_MIDI_MODE_INPUT)) {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
-		snd_emu10k1x_midi_cmd(emu, midi, MPU401_RESET, 0);
+		err = snd_emu10k1x_midi_cmd(emu, midi, MPU401_RESET, 0);
 	} else {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
 	}
-	return 0;
+	return err;
 }
 
 static void snd_emu10k1x_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
--- linux-2617-g21.orig/sound/pci/emu10k1/emumpu401.c
+++ linux-2617-g21/sound/pci/emu10k1/emumpu401.c
@@ -116,7 +116,7 @@ static void snd_emu10k1_midi_interrupt2(
 	do_emu10k1_midi_interrupt(emu, &emu->midi2, status);
 }
 
-static void snd_emu10k1_midi_cmd(struct snd_emu10k1 * emu, struct snd_emu10k1_midi *midi, unsigned char cmd, int ack)
+static int snd_emu10k1_midi_cmd(struct snd_emu10k1 * emu, struct snd_emu10k1_midi *midi, unsigned char cmd, int ack)
 {
 	unsigned long flags;
 	int timeout, ok;
@@ -141,11 +141,14 @@ static void snd_emu10k1_midi_cmd(struct 
 		ok = 1;
 	}
 	spin_unlock_irqrestore(&midi->input_lock, flags);
-	if (!ok)
+	if (!ok) {
 		snd_printk(KERN_ERR "midi_cmd: 0x%x failed at 0x%lx (status = 0x%x, data = 0x%x)!!!\n",
 			   cmd, emu->port,
 			   mpu401_read_stat(emu, midi),
 			   mpu401_read_data(emu, midi));
+		return 1;
+	}
+	return 0;
 }
 
 static int snd_emu10k1_midi_input_open(struct snd_rawmidi_substream *substream)
@@ -161,12 +164,17 @@ static int snd_emu10k1_midi_input_open(s
 	midi->substream_input = substream;
 	if (!(midi->midi_mode & EMU10K1_MIDI_MODE_OUTPUT)) {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
-		snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 1);
-		snd_emu10k1_midi_cmd(emu, midi, MPU401_ENTER_UART, 1);
+		if (snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 1))
+			goto error_out;
+		if (snd_emu10k1_midi_cmd(emu, midi, MPU401_ENTER_UART, 1))
+			goto error_out;
 	} else {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
 	}
 	return 0;
+
+error_out:
+	return -EIO;
 }
 
 static int snd_emu10k1_midi_output_open(struct snd_rawmidi_substream *substream)
@@ -182,12 +190,17 @@ static int snd_emu10k1_midi_output_open(
 	midi->substream_output = substream;
 	if (!(midi->midi_mode & EMU10K1_MIDI_MODE_INPUT)) {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
-		snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 1);
-		snd_emu10k1_midi_cmd(emu, midi, MPU401_ENTER_UART, 1);
+		if (snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 1))
+			goto error_out;
+		if (snd_emu10k1_midi_cmd(emu, midi, MPU401_ENTER_UART, 1))
+			goto error_out;
 	} else {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
 	}
 	return 0;
+
+error_out:
+	return -EIO;
 }
 
 static int snd_emu10k1_midi_input_close(struct snd_rawmidi_substream *substream)
@@ -195,6 +208,7 @@ static int snd_emu10k1_midi_input_close(
 	struct snd_emu10k1 *emu;
 	struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
 	unsigned long flags;
+	int err = 0;
 
 	emu = midi->emu;
 	snd_assert(emu, return -ENXIO);
@@ -204,11 +218,11 @@ static int snd_emu10k1_midi_input_close(
 	midi->substream_input = NULL;
 	if (!(midi->midi_mode & EMU10K1_MIDI_MODE_OUTPUT)) {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
-		snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 0);
+		err = snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 0);
 	} else {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
 	}
-	return 0;
+	return err;
 }
 
 static int snd_emu10k1_midi_output_close(struct snd_rawmidi_substream *substream)
@@ -216,6 +230,7 @@ static int snd_emu10k1_midi_output_close
 	struct snd_emu10k1 *emu;
 	struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
 	unsigned long flags;
+	int err = 0;
 
 	emu = midi->emu;
 	snd_assert(emu, return -ENXIO);
@@ -225,11 +240,11 @@ static int snd_emu10k1_midi_output_close
 	midi->substream_output = NULL;
 	if (!(midi->midi_mode & EMU10K1_MIDI_MODE_INPUT)) {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
-		snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 0);
+		err = snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 0);
 	} else {
 		spin_unlock_irqrestore(&midi->open_lock, flags);
 	}
-	return 0;
+	return err;
 }
 
 static void snd_emu10k1_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)

Re: [Ubuntu PATCH] FIx no mpu401 interface can cause hard freeze

[Andrew Morton]

On Mon, 03 Jul 2006 13:47:29 -0700
Randy Dunlap <randy.dunlap@oracle.com> wrote:

> This patch fixes the remaining instances in our tree where a non-
> existent mpu401 interface can cause a hard freeze when i/o is issued.
> 
> This commit closes Malone #34831.
> 
> Bug: https://launchpad.net/distros/ubuntu/+source/linux-source-2.6.15/+bug/34831
> 
> patch location:
> http://www.kernel.org/git/?p=linux/kernel/git/bcollins/ubuntu-dapper.git;a=commitdiff;h=b422309cdd980cfefe99379796c04e961d3c1544

Do we know who wrote this patch?

Re: [Ubuntu PATCH] FIx no mpu401 interface can cause hard freeze

[Daniel T. Chen]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

[Apologies in advance for duplicated subscribers]

Andrew Morton wrote:
>> http://www.kernel.org/git/?p=linux/kernel/git/bcollins/ubuntu-dapper.git;a=commitdiff;h=b422309cdd980cfefe99379796c04e961d3c1544
> 
> Do we know who wrote this patch?

It's mine. [0], [1], and [2] contain relevant context as well. The above
commit is insufficient as a fix; the current Ubuntu Dapper kernel
(2.6.15-25.43) does not have the patch from [2].

I have been unable to reproduce the hard freeze using Dapper's current
kernel, but others commenting in [0] are able. The patch from [2] only
seems to lessen the frequency of the freezes on certain hardware.

[0] http://launchpad.net/bugs/34831
[1] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=376382
[2] https://bugtrack.alsa-project.org/alsa-bug/view.php?id=952

Thanks,
- --
Daniel T. Chen            crimsun@ubuntu.com
GPG key:   www.sh.nu/~crimsun/pubkey.gpg.asc
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Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

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Re: [Ubuntu PATCH] FIx no mpu401 interface can cause hard freeze

[Clemens Ladisch]

Randy Dunlap wrote:
> This patch fixes the remaining instances in our tree where a non-
> existent mpu401 interface can cause a hard freeze when i/o is
> issued.
>
>  sound/pci/emu10k1/emu10k1x.c
>  sound/pci/emu10k1/emumpu401.c

These drivers are for chips where we know that an MPU-401 interface
exists.

Are there any freezes on these devices that can be resolved by this
patch?


Regards,
Clemens

Re: [Ubuntu PATCH] FIx no mpu401 interface can cause hard freeze

[Takashi Iwai]

At Tue, 04 Jul 2006 11:09:32 +0200,
Clemens Ladisch wrote:
> 
> Randy Dunlap wrote:
> > This patch fixes the remaining instances in our tree where a non-
> > existent mpu401 interface can cause a hard freeze when i/o is
> > issued.
> >
> >  sound/pci/emu10k1/emu10k1x.c
> >  sound/pci/emu10k1/emumpu401.c
> 
> These drivers are for chips where we know that an MPU-401 interface
> exists.
> 
> Are there any freezes on these devices that can be resolved by this
> patch?

Maybe this fix is irrelevant.  But it's anyway better to check the
errors there.

My rough guess of the culprit is the spin deadlock through
snd-rtctimer.


Takashi