Re: Nokia N900 - audio TPA6130A2 problems

Ivaylo Dimitrov
2016-03-17T14:59:03Z

Hi,

On 17.03.2016 16:32, Tony Lindgren wrote:
>
> Seems like a bug to me. My bets are on the deferred probe related
> Peter posted.
>

I will test Peter's patch as well, however I really doubt internal
pull-ups enabled by Nokia to be a bug - keep in mind there are (or at
least were) enough devices on the field for such a bug to not remain
unnoticed, esp if it directly affects the signal quality over the i2c bus.

>
> You can calculate the parallel resistor value of the weak internal
> pull with the 1k external pull :)

Sure :)

> If the i2c line pulls are wrong
> the signal quality won't match the spec and you will be getting
> i2c bus errors. If you can read and write to the i2c chip, this
> is not the issue.
>

And it seems stock kernel can read/write without problems with those
pull-ups enabled.

However, lets continue the discussion after I have tested both the
Peter's patch and internal pull-ups enabled.

Thanks,
Ivo