From: Wolfram Sang <wsa@the-dreams.de>
To: Joakim Tjernlund <Joakim.Tjernlund@infinera.com>
Cc: "oss@buserror.net" <oss@buserror.net>,
"linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>
Subject: Re: [PATCHv2] i2c-mpc: Correct I2C reset procedure
Date: Wed, 21 Jun 2017 23:59:24 +0200 [thread overview]
Message-ID: <20170621215924.GB2419@katana> (raw)
In-Reply-To: <20170621213647.GA2419@katana>
[-- Attachment #1: Type: text/plain, Size: 643 bytes --]
> Toggling 9x even means you could then write something somewhere
> which in case of a PMIC can be really dangerous.
I am partly wrong here because you send a START beforehand. And devices
are required to reset their state machine when they detect a START (I2C
Specs 3.1.10, Note 4). So, it *shouldn't* be dangerous. If all devices
follow that rule, that is...
However, you can only send START when SDA is not stuck. And still, this
whole toggling is to reanimate a stuck SDA. So, it still looks to me
that it doesn't make sense to have START & STOP around the toggling and
rather have a single STOP before you try toggling.
Makes sense?
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2017-06-21 21:59 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-11 12:20 [PATCHv2] i2c-mpc: Correct I2C reset procedure Joakim Tjernlund
2017-05-16 15:13 ` Joakim Tjernlund
2017-05-23 13:47 ` Joakim Tjernlund
2017-05-24 0:58 ` Scott Wood
2017-05-29 21:04 ` Wolfram Sang
2017-05-29 22:03 ` Joakim Tjernlund
2017-06-21 21:36 ` Wolfram Sang
2017-06-21 21:59 ` Wolfram Sang [this message]
2017-06-22 8:40 ` Joakim Tjernlund
2017-06-22 10:00 ` Wolfram Sang
2017-06-22 11:39 ` Joakim Tjernlund
2017-06-18 16:27 ` Joakim Tjernlund
2021-11-29 11:51 ` Wolfram Sang
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=20170621215924.GB2419@katana \
--to=wsa@the-dreams.de \
--cc=Joakim.Tjernlund@infinera.com \
--cc=linux-i2c@vger.kernel.org \
--cc=oss@buserror.net \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox