Re: Fw: PATCH: creating devices for multiple sound cards

[Chris Rankin]

Hi,

Here is the updated version of this patch,

Cheers,
Chris

--- drivers/sound/sound_core.c.orig	Tue Jul 31 18:26:12 2001
+++ drivers/sound/sound_core.c	Tue Jul 31 18:41:45 2001
@@ -17,7 +17,7 @@
  *	plug into this. The fact they dont all go via OSS doesn't mean 
  *	they don't have to implement the OSS API. There is a lot of logic
  *	to keeping much of the OSS weight out of the code in a compatibility
- *	module, but its up to the driver to rember to load it...
+ *	module, but its up to the driver to remember to load it...
  *
  *	The code provides a set of functions for registration of devices
  *	by type. This is done rather than providing a single call so that
@@ -173,10 +173,10 @@
 		return r;
 	}
 	
-	if (r == low)
+	if ( r < SOUND_STEP )
 		sprintf (name_buf, "%s", name);
 	else
-		sprintf (name_buf, "%s%d", name, (r - low) / SOUND_STEP);
+		sprintf (name_buf, "%s%d", name, (r / SOUND_STEP));
 	s->de = devfs_register (devfs_handle, name_buf,
 				DEVFS_FL_NONE, SOUND_MAJOR, s->unit_minor,
 				S_IFCHR | mode, fops, NULL);
@@ -231,9 +231,10 @@
  
 int register_sound_special(struct file_operations *fops, int unit)
 {
-	char *name;
+	const int chain = (unit & 0x0F);
+	const char *name;
 
-	switch (unit) {
+	switch (chain) {
 	    case 0:
 		name = "mixer";
 		break;
@@ -241,7 +242,7 @@
 		name = "sequencer";
 		break;
 	    case 2:
-		name = "midi00";
+		name = "midi";
 		break;
 	    case 3:
 		name = "dsp";
@@ -259,7 +260,7 @@
 		name = "unknown7";
 		break;
 	    case 8:
-		name = "sequencer2";
+		name = "music";
 		break;
 	    case 9:
 		name = "dmmidi";
@@ -283,7 +284,7 @@
 		name = "unknown";
 		break;
 	}
-	return sound_insert_unit(&chains[unit&15], fops, -1, unit, unit+1,
+	return sound_insert_unit(&chains[chain], fops, -1, unit, chain+128,
 				 name, S_IRUSR | S_IWUSR);
 }
  

> Why this patch was not applied (I checked 2.4.7)?
> 
> ------ Forwarded message ------
> From: Chris Rankin <[e-mail]>
> Date: Sat, 14 Apr 2001 09:44:35 +0200
> Subject: PATCH: creating devices for multiple sound cards
> To: [e-mail]
> 
> Hi,
> I have just installed a new sound card in my machine, and have left
> the built-in sound chip enabled despite the motherboard manufacturer's
> warning of Bad Things. The result is that I now have two sound devices
> in my machine - an ICH (i810_audio) and a Soundblaster Live! The Live!
> is device 0, of course. Anyway, I am using the ALSA drivers because
> the native i810_audio module caused a kernel panic (NULL pointer
> reference in an interrupt handler, I believe), and I have noticed that
> the ALSA drivers have difficulty creating OSS device nodes for both
> cards. I have traced the problem to the register_sound_special()
> function within Linux's soundcore.o module. Basically, ALSA uses this
> function to create OSS devices, but this function was never written
> with more than one sound device in mind. Until now.
> 
> A few points about this patch:
> 
> 1. I have renamed "sequencer2" to "music" because of a potential naming
> conflict between devices 14,8 ("music" on card 0) and 14,33 ("sequencer"
> on card 2).
> 
> 2. I have renamed device "midi00" to "midi". "midi01" now becomes "midi1"
> as well, although I would also point out that this is now consistent with
> the behaviour of the register_sound_midi() function.
> 
> Having applied this patch, ALSA gives me two mixer devices in /dev/sound,
> and I no longer get messages like these in my logs:
> 
> Apr 12 01:36:54 (none) kernel: devfs: devfs_register(): device already registered: "unknown"
> 
> Apr 12 01:40:04 (none) kernel: devfs: devfs_register(): device already registered: "mixer"
> Apr 12 01:40:04 (none) kernel: devfs: devfs_register(): device already registered: "dsp"