bug in spi and i2c dual buses codecs

bug in spi and i2c dual buses codecs

[Barry Song]

Hi Mark/Liam,
I think there is really a bug in spi and i2c dual buses codecs drivers, for
example, for any codec with two buses, if you config kernel like this:

SPI MASTER built-in
I2C                module
Codec           built-in

You will get a link error like this:
sound/built-in.o: In function `i2c_add_driver':
include/linux/i2c.h:423: undefined reference to `i2c_register_driver'
sound/built-in.o: In function `ad193x_modexit':
sound/soc/codecs/ad193x.c:537: undefined reference to `i2c_del_driver'
make: *** [.tmp_vmlinux1] Error 1

I remember that is also one reason why we have splitted this kind of driver
into three parts(codec core, i2c bus, spi bus).

In fact, if any bus is compiled as module and code is built-in, link error
will be reported.
Thanks
Barry

Re: bug in spi and i2c dual buses codecs

[Mark Brown]

On Mon, Mar 29, 2010 at 02:24:28PM +0800, Barry Song wrote:

> In fact, if any bus is compiled as module and code is built-in, link error
> will be reported.

Yes, this is expected behaviour.  It's not been a practical problem -
the combination of audio built in and one of the buses modular is far
from common.

Re: bug in spi and i2c dual buses codecs

[Barry Song]

On Mon, Mar 29, 2010 at 5:49 PM, Mark Brown
<broonie@opensource.wolfsonmicro.com> wrote:
>
> On Mon, Mar 29, 2010 at 02:24:28PM +0800, Barry Song wrote:
>
> > In fact, if any bus is compiled as module and code is built-in, link error
> > will be reported.
>
> Yes, this is expected behaviour.  It's not been a practical problem -
> the combination of audio built in and one of the buses modular is far
> from common.
Ok. if so, practically, people should either built-in all, or keep
codec driver as module if anyone of  i2c and spi is module.
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Re: [Uclinux-dist-devel] bug in spi and i2c dual buses codecs

[Mike Frysinger]

On Mon, Mar 29, 2010 at 05:49, Mark Brown wrote:
> On Mon, Mar 29, 2010 at 02:24:28PM +0800, Barry Song wrote:
>> In fact, if any bus is compiled as module and code is built-in, link error
>> will be reported.
>
> Yes, this is expected behaviour.  It's not been a practical problem -
> the combination of audio built in and one of the buses modular is far
> from common.

knowingly breaking randconfig is viewed as a bad thing by people on lkml
-mike
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Re: [alsa-devel] bug in spi and i2c dual buses codecs

[Mark Brown]

On Mon, Mar 29, 2010 at 02:25:02PM -0400, Mike Frysinger wrote:
> On Mon, Mar 29, 2010 at 05:49, Mark Brown wrote:

> > Yes, this is expected behaviour. ??It's not been a practical problem -
> > the combination of audio built in and one of the buses modular is far
> > from common.

> knowingly breaking randconfig is viewed as a bad thing by people on lkml

Right, the machine drivers need to take care of this when they select
the CODEC drivers like SND_SOC_ALL_CODECS does (at least with drivers
for the platforms where people care about that, anyway - I'm not going
to insist on it for random machines that hardly ever get built).

This isn't exactly something that's been introduced just recently, we've
been doing this for some considerable time - well over a year.