From: Tony Lindgren <tony@atomide.com>
To: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Cc: "Pali Rohár" <pali.rohar@gmail.com>,
"Sebastian Reichel" <sre@kernel.org>,
"Grygorii Strashko" <grygorii.strashko@ti.com>,
"Peter Ujfalusi" <peter.ujfalusi@ti.com>,
"Jarkko Nikula" <jarkko.nikula@bitmer.com>,
"Lars-Peter Clausen" <lars@metafoo.de>,
linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org,
"Pavel Machek" <pavel@ucw.cz>,
"Aaro Koskinen" <aaro.koskinen@iki.fi>,
"Nishanth Menon" <nm@ti.com>,
merlijn@wizzup.org
Subject: Re: Nokia N900 - audio TPA6130A2 problems
Date: Thu, 17 Mar 2016 07:32:05 -0700 [thread overview]
Message-ID: <20160317143204.GM9329@atomide.com> (raw)
In-Reply-To: <56EAB62D.80803@gmail.com>
* Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> [160317 06:51]:
> Hi,
>
> On 17.03.2016 15:33, Tony Lindgren wrote:
> >
> >Check the schematics. If the hardware has external pull-ups on a
> >line then don't enable the internal pull-ups. Otherwise both the
> >external and intenal pulls are parallel the pull value will be
> >wrong. My guess is that on n900 all the i2c lines have external
> >pulls.
>
> There are, 1k connected to VIO_18, but still, stock Nokia kernel enables the
> internal pull-ups as well. I doubt Nokia devs did that by mistake. Could it
> be that VIO_18 is disabled by the time TPA6130A2 is probed?
Seems like a bug to me. My bets are on the deferred probe related
Peter posted.
> Also, what is the problem to have both internal and external pull-ups in
> parallel?
You can calculate the parallel resistor value of the weak internal
pull with the 1k external pull :) 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.
Regards,
Tony
next prev parent reply other threads:[~2016-03-17 14:32 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-25 10:28 Nokia N900 - audio TPA6130A2 problems Pali Rohár
2015-07-25 10:28 ` Pali Rohár
2015-07-25 13:17 ` Lars-Peter Clausen
2015-08-01 10:18 ` Pali Rohár
2015-08-03 18:03 ` Jarkko Nikula
2015-08-03 18:17 ` Pali Rohár
2015-08-03 18:48 ` Jarkko Nikula
2015-08-03 18:55 ` Pali Rohár
2015-08-04 7:02 ` Peter Ujfalusi
2015-08-04 7:02 ` Peter Ujfalusi
2016-01-04 23:34 ` Pali Rohár
2016-03-06 15:23 ` Sebastian Reichel
2016-03-07 11:59 ` Pali Rohár
2016-03-08 6:45 ` Ivaylo Dimitrov
2016-03-12 12:39 ` Pali Rohár
2016-03-12 12:42 ` Pali Rohár
2016-03-14 9:59 ` Peter Ujfalusi
2016-03-14 9:59 ` Peter Ujfalusi
2016-03-14 17:05 ` Ivaylo Dimitrov
2016-03-16 13:33 ` Pali Rohár
2016-03-16 14:47 ` Sebastian Reichel
2016-03-16 18:21 ` Ivaylo Dimitrov
2016-03-16 18:32 ` Grygorii Strashko
2016-03-16 18:32 ` Grygorii Strashko
2016-03-16 19:50 ` Ivaylo Dimitrov
2016-03-17 0:49 ` Sebastian Reichel
2016-03-17 7:56 ` Ivaylo Dimitrov
2016-03-17 13:01 ` Pali Rohár
2016-03-17 13:11 ` Ivaylo Dimitrov
2016-03-17 13:33 ` Tony Lindgren
2016-03-17 13:50 ` Ivaylo Dimitrov
2016-03-17 14:32 ` Tony Lindgren [this message]
2016-03-17 14:58 ` Ivaylo Dimitrov
2016-03-17 7:53 ` Peter Ujfalusi
2016-03-17 7:53 ` Peter Ujfalusi
2016-03-17 17:26 ` Ivaylo Dimitrov
2016-03-18 10:33 ` Peter Ujfalusi
2016-03-18 10:33 ` Peter Ujfalusi
2016-03-18 13:13 ` Ивайло Димитров
2016-03-18 13:36 ` Sebastian Reichel
2016-03-18 13:45 ` Ivaylo Dimitrov
2016-03-18 15:04 ` Sebastian Reichel
2016-03-18 15:56 ` Ivaylo Dimitrov
2016-03-19 8:49 ` Ivaylo Dimitrov
2016-03-20 5:17 ` Sebastian Reichel
2016-03-20 19:43 ` Ivaylo Dimitrov
2016-03-21 0:04 ` Sebastian Reichel
2016-03-21 1:40 ` Sebastian Reichel
2016-03-21 12:03 ` Mark Brown
2016-03-21 11:45 ` Mark Brown
2016-03-21 13:39 ` Ivaylo Dimitrov
2016-03-21 13:45 ` Mark Brown
2016-03-21 14:53 ` Sebastian Reichel
2016-03-21 19:34 ` Ivaylo Dimitrov
2016-03-22 8:02 ` Ivaylo Dimitrov
2016-04-01 10:43 ` Race condition in TPA6130A2 (Was: Re: Nokia N900 - audio TPA6130A2 problems) Pali Rohár
2015-08-14 20:46 ` Nokia N900 - audio TPA6130A2 problems Pavel Machek
2015-08-14 20:54 ` Pali Rohár
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160317143204.GM9329@atomide.com \
--to=tony@atomide.com \
--cc=aaro.koskinen@iki.fi \
--cc=grygorii.strashko@ti.com \
--cc=ivo.g.dimitrov.75@gmail.com \
--cc=jarkko.nikula@bitmer.com \
--cc=lars@metafoo.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=merlijn@wizzup.org \
--cc=nm@ti.com \
--cc=pali.rohar@gmail.com \
--cc=pavel@ucw.cz \
--cc=peter.ujfalusi@ti.com \
--cc=sre@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.