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From: Antti Palosaari <crope@iki.fi>
To: linux-media@vger.kernel.org, David Daney <david.daney@cavium.com>
Subject: Re: recursive locking problem
Date: Wed, 14 Sep 2011 04:03:58 +0300	[thread overview]
Message-ID: <4E6FFD7E.2060500@iki.fi> (raw)
In-Reply-To: <20110909114634.GA22776@minime.bse>

On 09/09/2011 02:46 PM, Daniel Glöckner wrote:
> On Thu, Sep 08, 2011 at 07:34:32PM +0300, Antti Palosaari wrote:
>> I am working with AF9015 I2C-adapter lock. I need lock I2C-bus since
>> there is two tuners having same I2C address on same bus, demod I2C
>> gate is used to select correct tuner.
>
> Would it be possible to use the i2c-mux framework to handle this?
> Each tuner will then have its own i2c bus.

Interesting idea, but it didn't worked. It deadlocks. I think it locks 
since I2C-mux is controlled by I2C "switch" in same I2C bus, not GPIO or 
some other HW.

* tuner does I2C xfer on I2C-mux adapter
* I2C-mux adapter calls demod .i2c_gate_ctrl()
* demod does register access using I2C
* DEADLOCK

Maybe since tuner I2C xfer have already locked I2C-adater. Then demod 
access same adapter and it is locked.

But nice I2C mux anyhow.

@David Daney, see that pic in order to get understanding what kind of 
problem I am working;
http://palosaari.fi/linux/v4l-dv/controlling_tuner_af9015_dual_demod.txt


regards
Antti


-- 
http://palosaari.fi/

  reply	other threads:[~2011-09-14  1:04 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-08 16:34 recursive locking problem Antti Palosaari
2011-09-09  7:51 ` Hans Petter Selasky
2011-09-09 10:45 ` David Waring
2011-09-13 20:59   ` Antti Palosaari
2011-09-13 21:34     ` Steve Kerrison
2011-09-13 21:58       ` Steven Toth
2011-09-13 22:10         ` Devin Heitmueller
2011-09-13 22:19           ` Steven Toth
2011-09-13 22:01       ` Devin Heitmueller
2011-09-09 11:46 ` Daniel Glöckner
2011-09-14  1:03   ` Antti Palosaari [this message]
2011-09-14  6:19     ` Daniel Glöckner
2011-09-14 10:45       ` Antti Palosaari
2011-09-14 12:22         ` Daniel Glöckner

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