Re: Nokia N900 - audio TPA6130A2 problems

From: Ivaylo Dimitrov
Date: Thu Mar 17 2016 - 10:59:05 EST


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