[PATCH] Fix Alsa issues including Oopses with OSS emulation

[PATCH] Fix Alsa issues including Oopses with OSS emulation

[Benjamin Herrenschmidt]

This patch (which will be send upstream separately by the Alsa folks) fixes
an signed vs. unsigned char problem in Alsa which was the cause of the Oops
people were experiencing on ppc with OSS emulation and possibly other issues.

Index: linux-work/sound/core/pcm_misc.c
===================================================================
--- linux-work.orig/sound/core/pcm_misc.c	2004-11-22 01:51:09.000000000 +0100
+++ linux-work/sound/core/pcm_misc.c	2004-12-22 19:11:26.297518336 +0100
@@ -26,10 +26,10 @@
 #define SND_PCM_FORMAT_UNKNOWN (-1)
 
 struct pcm_format_data {
-	char width;	/* bit width */
-	char phys;	/* physical bit width */
-	char le;	/* 0 = big-endian, 1 = little-endian, -1 = others */
-	char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
+	signed char width;	/* bit width */
+	signed char phys;	/* physical bit width */
+	signed char le;		/* 0 = big-endian, 1 = little-endian, -1 = others */
+	signed char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
 	unsigned char silence[8];	/* silence data to fill */
 };
 

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Benjamin Herrenschmidt]

On Wed, 2004-12-22 at 19:13 +0100, Benjamin Herrenschmidt wrote:
> This patch (which will be send upstream separately by the Alsa folks) fixes
> an signed vs. unsigned char problem in Alsa which was the cause of the Oops
> people were experiencing on ppc with OSS emulation and possibly other issues.

Ok, actually, the one that will be commited upstream is a bit different,
here it is:


Summary: [ALSA] Fix the wrong sign of format data entries

Fix suggested by Benjamin Herrenschmidt <benh@kernel.crashing.org>

On architectures like PPC, char is handled as "unsigned char", thus the
pcm_format_data table entries with -1 give a positive 255.  This causes
Oops with OSS-emulation on such architectures.

The patch simply adds the right signed/unsigned prefix to fix this problem.


Signed-off-by: Takashi Iwai <tiwai@suse.de>


--- linux/sound/core/pcm_misc.c 8 Jun 2004 16:57:28 -0000       1.12
+++ linux/sound/core/pcm_misc.c 22 Dec 2004 18:07:29 -0000      1.14
@@ -25,11 +25,14 @@
 #include <sound/pcm.h>
 #define SND_PCM_FORMAT_UNKNOWN (-1)
 
+/* NOTE: "signed" prefix must be given below since the default char is
+ *       unsigned on some architectures!
+ */
 struct pcm_format_data {
-       char width;     /* bit width */
-       char phys;      /* physical bit width */
-       char le;        /* 0 = big-endian, 1 = little-endian, -1 = others */
-       char signd;     /* 0 = unsigned, 1 = signed, -1 = others */
+       unsigned char width;    /* bit width */
+       unsigned char phys;     /* physical bit width */
+       signed char le; /* 0 = big-endian, 1 = little-endian, -1 = others */
+       signed char signd;      /* 0 = unsigned, 1 = signed, -1 = others */
        unsigned char silence[8];       /* silence data to fill */
 };

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Sven Luther]

On Wed, Dec 22, 2004 at 07:35:13PM +0100, Benjamin Herrenschmidt wrote:
> On Wed, 2004-12-22 at 19:13 +0100, Benjamin Herrenschmidt wrote:
> > This patch (which will be send upstream separately by the Alsa folks) fixes
> > an signed vs. unsigned char problem in Alsa which was the cause of the Oops
> > people were experiencing on ppc with OSS emulation and possibly other issues.
> 
> Ok, actually, the one that will be commited upstream is a bit different,
> here it is:

Ben, i suppose this one is for inclusion in the debian kernel too, do you
think you could send such patches as bug reports against kernel-source-2.6.8
package, or to debian-kernel also ? 

Friendly,

Sven Luther

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Benjamin Herrenschmidt]

On Thu, 2004-12-23 at 07:25 +0100, Sven Luther wrote:
> On Wed, Dec 22, 2004 at 07:35:13PM +0100, Benjamin Herrenschmidt wrote:
> > On Wed, 2004-12-22 at 19:13 +0100, Benjamin Herrenschmidt wrote:
> > > This patch (which will be send upstream separately by the Alsa folks) fixes
> > > an signed vs. unsigned char problem in Alsa which was the cause of the Oops
> > > people were experiencing on ppc with OSS emulation and possibly other issues.
> > 
> > Ok, actually, the one that will be commited upstream is a bit different,
> > here it is:
> 
> Ben, i suppose this one is for inclusion in the debian kernel too, do you
> think you could send such patches as bug reports against kernel-source-2.6.8
> package, or to debian-kernel also ? 

Wherever as long as it gets into the debian kernel packages. I doesn't
affect ppc only (any arch with unsigned char by default)

Ben.

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Sven Luther]

On Thu, Dec 23, 2004 at 07:55:02AM +0100, Benjamin Herrenschmidt wrote:
> On Thu, 2004-12-23 at 07:25 +0100, Sven Luther wrote:
> > On Wed, Dec 22, 2004 at 07:35:13PM +0100, Benjamin Herrenschmidt wrote:
> > > On Wed, 2004-12-22 at 19:13 +0100, Benjamin Herrenschmidt wrote:
> > > > This patch (which will be send upstream separately by the Alsa folks) fixes
> > > > an signed vs. unsigned char problem in Alsa which was the cause of the Oops
> > > > people were experiencing on ppc with OSS emulation and possibly other issues.
> > > 
> > > Ok, actually, the one that will be commited upstream is a bit different,
> > > here it is:
> > 
> > Ben, i suppose this one is for inclusion in the debian kernel too, do you
> > think you could send such patches as bug reports against kernel-source-2.6.8
> > package, or to debian-kernel also ? 
> 
> Wherever as long as it gets into the debian kernel packages. I doesn't
> affect ppc only (any arch with unsigned char by default)

Ok, i will include it, but i am asking that next time you post to
debian-kernel or better yet open a bug report (reportbug kernel should do), in
order for such patches not to get lost in debian-powerpc.

Friendly,

Sven Luther

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Sven Luther]

On Wed, Dec 22, 2004 at 07:35:13PM +0100, Benjamin Herrenschmidt wrote:
> On Wed, 2004-12-22 at 19:13 +0100, Benjamin Herrenschmidt wrote:
> > This patch (which will be send upstream separately by the Alsa folks) fixes
> > an signed vs. unsigned char problem in Alsa which was the cause of the Oops
> > people were experiencing on ppc with OSS emulation and possibly other issues.
> 
> Ok, actually, the one that will be commited upstream is a bit different,
> here it is:
> 
> 
> Summary: [ALSA] Fix the wrong sign of format data entries
> 
> Fix suggested by Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 
> On architectures like PPC, char is handled as "unsigned char", thus the
> pcm_format_data table entries with -1 give a positive 255.  This causes
> Oops with OSS-emulation on such architectures.
> 
> The patch simply adds the right signed/unsigned prefix to fix this problem.
> 
> 
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> 
> 
> --- linux/sound/core/pcm_misc.c 8 Jun 2004 16:57:28 -0000       1.12
> +++ linux/sound/core/pcm_misc.c 22 Dec 2004 18:07:29 -0000      1.14
> @@ -25,11 +25,14 @@
>  #include <sound/pcm.h>
>  #define SND_PCM_FORMAT_UNKNOWN (-1)
>  
> +/* NOTE: "signed" prefix must be given below since the default char is
> + *       unsigned on some architectures!
> + */
>  struct pcm_format_data {
> -       char width;     /* bit width */
> -       char phys;      /* physical bit width */
> -       char le;        /* 0 = big-endian, 1 = little-endian, -1 = others */
> -       char signd;     /* 0 = unsigned, 1 = signed, -1 = others */
> +       unsigned char width;    /* bit width */
> +       unsigned char phys;     /* physical bit width */
> +       signed char le; /* 0 = big-endian, 1 = little-endian, -1 = others */
> +       signed char signd;      /* 0 = unsigned, 1 = signed, -1 = others */
>         unsigned char silence[8];       /* silence data to fill */
>  };

Mmm, this does not apply to the 2.6.8 debian kernel-source package, which
doesn't seem to have a pcm_format_data structure. Do we need a backport of it
to 2.6.8, or was the problem not present then ? 

Friendly,

Sven Luther

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Martin-Éric Racine]

Nice to know that work is being done on the pmac ALSA driver. :)

However, I still cannot get ALSA to work at all on this iMac's Burgundy: =
=20
https://bugtrack.alsa-project.org/alsa-bug/view.php?id=3D306

The old OSS driver still works, so I know that the hardware is not at
fault; this is clearly an ALSA driver problem.

Has anybody managed to get this to work on similar hardware?


On Wed, 22 Dec 2004, Benjamin Herrenschmidt wrote:

> This patch (which will be send upstream separately by the Alsa folks) fix=
es
> an signed vs. unsigned char problem in Alsa which was the cause of the Oo=
ps
> people were experiencing on ppc with OSS emulation and possibly other iss=
ues.
>=20
> Index: linux-work/sound/core/pcm_misc.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- linux-work.orig/sound/core/pcm_misc.c=092004-11-22 01:51:09.000000000=
 +0100
> +++ linux-work/sound/core/pcm_misc.c=092004-12-22 19:11:26.297518336 +010=
0
> @@ -26,10 +26,10 @@
>  #define SND_PCM_FORMAT_UNKNOWN (-1)
> =20
>  struct pcm_format_data {
> -=09char width;=09/* bit width */
> -=09char phys;=09/* physical bit width */
> -=09char le;=09/* 0 =3D big-endian, 1 =3D little-endian, -1 =3D others */
> -=09char signd;=09/* 0 =3D unsigned, 1 =3D signed, -1 =3D others */
> +=09signed char width;=09/* bit width */
> +=09signed char phys;=09/* physical bit width */
> +=09signed char le;=09=09/* 0 =3D big-endian, 1 =3D little-endian, -1 =3D=
 others */
> +=09signed char signd;=09/* 0 =3D unsigned, 1 =3D signed, -1 =3D others *=
/
>  =09unsigned char silence[8];=09/* silence data to fill */
>  };
> =20
>=20
>=20
>=20
>=20

--=20
Martin-=C9ric Racine, ICT Consultant
http://www.iki.fi/q-funk/

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Dean Hamstead]

the pmac driver has issues on my imac dv, it works but alas
it doesnt know what to do when plugging in headphones
not to mention lack of input sensors for my ibook (clamshell)

i realise though that if you cant get specs and no one
wants to tinker around stuff wont get implemented.
but if its in OSS...

*shrug*

ben (and others) do a great job though.

Dean

Martin-Éric Racine wrote:
> Nice to know that work is being done on the pmac ALSA driver. :)
> 
> However, I still cannot get ALSA to work at all on this iMac's Burgundy:  
> https://bugtrack.alsa-project.org/alsa-bug/view.php?id=306
> 
> The old OSS driver still works, so I know that the hardware is not at
> fault; this is clearly an ALSA driver problem.
> 
> Has anybody managed to get this to work on similar hardware?
> 
> 
> On Wed, 22 Dec 2004, Benjamin Herrenschmidt wrote:
> 
> 
>>This patch (which will be send upstream separately by the Alsa folks) fixes
>>an signed vs. unsigned char problem in Alsa which was the cause of the Oops
>>people were experiencing on ppc with OSS emulation and possibly other issues.
>>
>>Index: linux-work/sound/core/pcm_misc.c
>>===================================================================
>>--- linux-work.orig/sound/core/pcm_misc.c	2004-11-22 01:51:09.000000000 +0100
>>+++ linux-work/sound/core/pcm_misc.c	2004-12-22 19:11:26.297518336 +0100
>>@@ -26,10 +26,10 @@
>> #define SND_PCM_FORMAT_UNKNOWN (-1)
>> 
>> struct pcm_format_data {
>>-	char width;	/* bit width */
>>-	char phys;	/* physical bit width */
>>-	char le;	/* 0 = big-endian, 1 = little-endian, -1 = others */
>>-	char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
>>+	signed char width;	/* bit width */
>>+	signed char phys;	/* physical bit width */
>>+	signed char le;		/* 0 = big-endian, 1 = little-endian, -1 = others */
>>+	signed char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
>> 	unsigned char silence[8];	/* silence data to fill */
>> };
>> 
>>
>>
>>
>>
> 
> 

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Benjamin Herrenschmidt]

On Thu, 2004-12-23 at 11:15 +1100, Dean Hamstead wrote:
> the pmac driver has issues on my imac dv, it works but alas
> it doesnt know what to do when plugging in headphones
> not to mention lack of input sensors for my ibook (clamshell)
> 
> i realise though that if you cant get specs and no one
> wants to tinker around stuff wont get implemented.
> but if its in OSS...

Well, there are specs: the Darwin sources are available for all of Apple
sound drivers. It's just that there are approx. as many HW setups as
motherboards, so it's a bit of a mess, and I don't have much time to dig
into it (and I didn't write the Alsa driver).

But others are welcome to work on it & propose patches :)

Ben.

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Dean Hamstead]

given the variety of hardware would it be worth splitting up snd-powermac?

how easily can code be used from darwin?

Dean

Benjamin Herrenschmidt wrote:

>On Thu, 2004-12-23 at 11:15 +1100, Dean Hamstead wrote:
>  
>
>>the pmac driver has issues on my imac dv, it works but alas
>>it doesnt know what to do when plugging in headphones
>>not to mention lack of input sensors for my ibook (clamshell)
>>
>>i realise though that if you cant get specs and no one
>>wants to tinker around stuff wont get implemented.
>>but if its in OSS...
>>    
>>
>
>Well, there are specs: the Darwin sources are available for all of Apple
>sound drivers. It's just that there are approx. as many HW setups as
>motherboards, so it's a bit of a mess, and I don't have much time to dig
>into it (and I didn't write the Alsa driver).
>
>But others are welcome to work on it & propose patches :)
>
>Ben.
>
>
>
>  
>

-- 
WWW: http://dean.bong.com.au  LAN: http://www.bong.com.au
EMAIL: dean@bong.com.au       or       djzort@bong.com.au
ICQ: 16867613

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Benjamin Herrenschmidt]

On Thu, 2004-12-23 at 23:25 +1100, Dean Hamstead wrote:
> given the variety of hardware would it be worth splitting up snd-powermac?
> 
> how easily can code be used from darwin?

Code cannot be copied "as-is" but it's definitely a good source of
informations. Also, the various codec chips used on recent machines do
have publically available documentations.

What I would suggest is to split the driver for all the pre-i2s machines
(awacs, screamer & burgundy basically) from the i2s based ones (daca,
tumbler, snapper, plus the g5 new digital stuff).

The actual dbdma code for doing the actual sample transfer & buffer
management should be split in a separate file and shared by all
implementations.

For the i2s based machines, we need a better mecanism. We need, I think,
to have a file with i2s stuffs (for dealing with setting the i2s sample
format & clocks, which we don't do properly yet), separate files for the
actual codecs (either analog or digital), and a "hub" part that puts
everything together.

The thing here is we need to deal with more than one codec on the same
bus (the g5 has both a tas3004 for analog and some other digital chip
for spdif) and we need to be able to change the clock source (when a
digital input is plugged, the whole clock net is to be sourced from it).

So I would suggest writing a "generic" interface structure (a structure
with function pointers etc...) for the codecs. The "core" code would
then match against the mac-io device of the i2s bus (it will match twice
but the second bus is used only by the modem and can be ignored for now)
or with whatever snapper/tumbler/AOA device node is below. It would
decode the "reg" property in there (slightly different on the G5s) and
instanciate the i2s driver the dbdma engine (PCM) and the appropriate
set of codec's. The codecs can register their own mixer controls
individually, but the "core" stuff need to deal with clock switching.

Ben.

Re: [PATCH] Fix Alsa issues including Oopses with OSS emulation

[Benjamin Herrenschmidt]

On Thu, 2004-12-23 at 01:36 +0200, Martin-Éric Racine wrote:
> Nice to know that work is being done on the pmac ALSA driver. :)
> 
> However, I still cannot get ALSA to work at all on this iMac's Burgundy:  
> https://bugtrack.alsa-project.org/alsa-bug/view.php?id=306
> 
> The old OSS driver still works, so I know that the hardware is not at
> fault; this is clearly an ALSA driver problem.
> 
> Has anybody managed to get this to work on similar hardware?

I don't have any of such hardware, but you are welcome to compare the
drivers and help debug it :)

Ben.