On Wed, Sep 14, 2011 at 01:45:47PM +0300, Antti Palosaari wrote:
> >>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.
> >
> >Take a look at drivers/i2c/muxes/pca954x.c. You need to
On 09/14/2011 09:19 AM, Daniel Glöckner wrote:
On Wed, Sep 14, 2011 at 04:03:58AM +0300, Antti Palosaari wrote:
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
t
On Wed, Sep 14, 2011 at 04:03:58AM +0300, Antti Palosaari wrote:
> 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 addr
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
> I would take Steven Toth's explanation as more authoritative than mine
> any day of the week. It's possible that I may have been misinformed
> regarding the rationale for why the gate is required.
In general, complete bus isolation lowers noise levels, whether
through RF coupling or needless in
On Tue, Sep 13, 2011 at 5:58 PM, Steven Toth wrote:
>> Can any one shed some light on this? I appreciate it's not a linux or
>> indeed linux-media specific issue as the hardware itself is designed
>> this way.
>
> i2c gates exist to isolate the downstream components from any spurious
> RF noise ge
On Tue, Sep 13, 2011 at 5:34 PM, Steve Kerrison wrote:
> At the risk of sounding silly, why do we rely on i2c gating so much? The
> whole point of i2c is that you can sit a bunch of devices on the same
> pair of wires and talk to one at a time.
Steve,
There are essentially two issues here. To a
> Can any one shed some light on this? I appreciate it's not a linux or
> indeed linux-media specific issue as the hardware itself is designed
> this way.
i2c gates exist to isolate the downstream components from any spurious
RF noise generated by noisy components on the i2c bus. You don't want
to
At the risk of sounding silly, why do we rely on i2c gating so much? The
whole point of i2c is that you can sit a bunch of devices on the same
pair of wires and talk to one at a time.
Why not just open up the gates and be done with it, except for
situations where the i2c chain foolishly has two de
On 09/09/2011 01:45 PM, David Waring wrote:
On 08/09/11 17:34, Antti Palosaari wrote:
[snip]
Is there any lock can do recursive locking but unlock frees all locks?
Like that:
gate_open
+gate_open
+gate_close
== lock is free
AFAIK mutex can do only simple lock() + unlock(). Semaphore can do
re
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
On 08/09/11 17:34, Antti Palosaari wrote:
> [snip]
>
> Is there any lock can do recursive locking but unlock frees all locks?
>
> Like that:
> gate_open
> +gate_open
> +gate_close
> == lock is free
>
> AFAIK mutex can do only simple lock() + unlock(). Semaphore can do
> recursive locking, like l
On Thursday 08 September 2011 18:34:32 Antti Palosaari wrote:
> lock() + lock() + unlock() == free.
Hi,
As far as I can see the Linux kernel's mutex API doesn't have support for
checking if a mutex is owned. I guess you would have to do something like:
while (mutex_owned(&xxx))
mutex_un
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.
I am trapping demod .i2c_gate_ctrl() calls and locking bus according to
that.
Is there any lock can do recursive locki
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