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From: Jean Delvare <khali@linux-fr•org>
To: Johannes Berg <johannes@sipsolutions•net>
Cc: Benjamin, linuxppc-dev@ozlabs•org, alsa-devel@alsa-project•org,
	Takashi Iwai <tiwai@suse•de>
Subject: Re: [PATCH] AOA: Convert onyx and tas codecs to new-style i2c drivers
Date: Wed, 15 Apr 2009 15:52:36 +0200	[thread overview]
Message-ID: <20090415155236.379479b7@hyperion.delvare> (raw)
In-Reply-To: <1239801490.9071.11.camel@johannes.local>

On Wed, 15 Apr 2009 15:18:10 +0200, Johannes Berg wrote:
> On Wed, 2009-04-15 at 15:06 +0200, Jean Delvare wrote:
> > Yes, i2c core or even driver core. I'll see if I can reproduce it.
> 
> Alright.

Hmm, couldn't reproduce it. Maybe it is fixed in rc2. I don't have too
much time to spend on this, so if we don't hit it again I consider it
solved.

> > (...)
> > What I had in mind was not so complex. Simply, we could move the
> > i2c_new_device() calls into layout_found_codec(). That way we can
> > decide to instantiate the I2C device if and only if check_codec() is
> > successful. This is more efficient that creating the device, letting
> > the driver attach to it, with probing eventually failing, and then
> > removing the device if it wasn't the right one.
> > 
> > That is, the i2c client would be a mere helper on top of struct
> > aoa_codec, rather than the other way around.
> 
> Ah. That would probably work, but right now I have little motivation to
> work on it -- I hardly use the G5 desktop machine any more.

OK, no problem. I don't want to force anyone to spend time on this. But
if anyone ever does and need my help for the i2c part, just drop me a
line!

> > Wow. One I2C device which can be reached through 2 different I2C buses?
> > First time I hear about something like this. Very odd. I can't see the
> > point of doing this.
> 
> Hmm. How do you know it's on different buses?

2-0046 fails and 3-0046 succeeds. The second number is the hexadecimal
I2C address, the first number is the I2C bus number. So, unless
i2c-powermac was told to register the same I2C bus twice (which would
be dangerous), the device can be accessed through 2 different buses.

> I don't really know
> anything -- all I know is that the DT is buggered and lists the codec
> twice. Since we can talk to both, then I'm sure it's just one chip, they
> wouldn't put the chip in twice when you can use only one of them :)

There's probably little point in trying to guess anything further, the
only thing that would help are the detailed schematics of that part of
the board.

-- 
Jean Delvare

  reply	other threads:[~2009-04-15 13:52 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-08 13:02 [PATCH] AOA: Convert onyx and tas codecs to new-style i2c drivers Jean Delvare
2009-04-08 15:51 ` Johannes Berg
2009-04-08 20:48   ` Jean Delvare
2009-04-09  7:44     ` Johannes Berg
2009-04-09 12:19       ` Jean Delvare
2009-04-09 12:34         ` Johannes Berg
2009-04-09 14:21           ` Jean Delvare
2009-04-10 15:02         ` Jean Delvare
2009-04-14 14:37           ` Jean Delvare
2009-04-14 14:45             ` Takashi Iwai
2009-04-16  7:53               ` Jean Delvare
2009-04-16  7:56                 ` Takashi Iwai
2009-04-14 15:40         ` Johannes Berg
2009-04-14 15:50           ` Johannes Berg
2009-04-14 16:57             ` Jean Delvare
2009-04-14 17:41             ` Johannes Berg
2009-04-14 19:49               ` Jean Delvare
2009-04-14 21:59                 ` Johannes Berg
2009-04-15 12:15                   ` Jean Delvare
2009-04-15 12:52                     ` Johannes Berg
2009-04-15 13:06                       ` Jean Delvare
2009-04-15 13:18                         ` Johannes Berg
2009-04-15 13:52                           ` Jean Delvare [this message]
2009-04-14 22:48                 ` Andreas Schwab
2009-04-15  8:19                   ` Jean Delvare
2009-04-14 16:48           ` Andreas Schwab
2009-04-14 17:20             ` Johannes Berg
  -- strict thread matches above, loose matches on Subject: below --
2009-04-20 20:54 Jean Delvare
2009-04-20 21:04 ` Johannes Berg
2009-04-21  9:29   ` Jean Delvare
2009-04-21  9:41     ` Johannes Berg
2009-04-21  6:30 ` Takashi Iwai

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