All of lore.kernel.org
 help / color / mirror / Atom feed
From: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
To: Maxime Coquelin <maxime.coquelin-qxv4g6HH51o@public.gmane.org>
Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Srinivas Kandagatla
	<srinivas.kandagatla-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Patrice Chotard <patrice.chotard-qxv4g6HH51o@public.gmane.org>,
	kernel-F5mvAk5X5gdBDgjK7y7TUQ@public.gmane.org
Subject: Re: [PATCH] drivers: i2c: i2c-st: Update i2c timings
Date: Mon, 21 Jul 2014 16:03:10 +0200	[thread overview]
Message-ID: <20140721140309.GA2734@katana> (raw)
In-Reply-To: <53CCF3EC.6030904-qxv4g6HH51o@public.gmane.org>

[-- Attachment #1: Type: text/plain, Size: 1074 bytes --]


> Sorry for the late reply, but it took time to get the answer.

No problem, thanks for keeping at it.

> > Which also came from the HW guys? Please ask for details why 10%, too.
> 
> This is a safety margin.

I understood that. Still why 10%? Is it randomly guessed? Was 5% the
first working value, so we took this * 2? Is it a secret value from a
well-experienced engineer? While not perfect, I'd accept those reasons
as long as they are clearly stated. I just want to avoid trial and error
trying to find a good value.

> Note that the I2C specification only defines minimal timings.
> 
> Is it fine for you?
> Can I re-send a v2, which:
>  - Indicate the Toshiba TV is one of the affected devices in the commit message
>  - Indicate the 10% margin is a safety one in the commit message
>  - Add a comment above the table indicating these are standard timings + 10% margin.

Basically yes. The same information should be in the commit message and
the comment above the table. I'd really like a short reason why 10%.

Regards,

    Wolfram


[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

WARNING: multiple messages have this Message-ID (diff)
From: Wolfram Sang <wsa@the-dreams.de>
To: Maxime Coquelin <maxime.coquelin@st.com>
Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
	Srinivas Kandagatla <srinivas.kandagatla@gmail.com>,
	Patrice Chotard <patrice.chotard@st.com>,
	kernel@stlinux.com
Subject: Re: [PATCH] drivers: i2c: i2c-st: Update i2c timings
Date: Mon, 21 Jul 2014 16:03:10 +0200	[thread overview]
Message-ID: <20140721140309.GA2734@katana> (raw)
In-Reply-To: <53CCF3EC.6030904@st.com>

[-- Attachment #1: Type: text/plain, Size: 1074 bytes --]


> Sorry for the late reply, but it took time to get the answer.

No problem, thanks for keeping at it.

> > Which also came from the HW guys? Please ask for details why 10%, too.
> 
> This is a safety margin.

I understood that. Still why 10%? Is it randomly guessed? Was 5% the
first working value, so we took this * 2? Is it a secret value from a
well-experienced engineer? While not perfect, I'd accept those reasons
as long as they are clearly stated. I just want to avoid trial and error
trying to find a good value.

> Note that the I2C specification only defines minimal timings.
> 
> Is it fine for you?
> Can I re-send a v2, which:
>  - Indicate the Toshiba TV is one of the affected devices in the commit message
>  - Indicate the 10% margin is a safety one in the commit message
>  - Add a comment above the table indicating these are standard timings + 10% margin.

Basically yes. The same information should be in the commit message and
the comment above the table. I'd really like a short reason why 10%.

Regards,

    Wolfram


[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

  parent reply	other threads:[~2014-07-21 14:03 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-16 15:32 [PATCH] drivers: i2c: i2c-st: Update i2c timings Maxime COQUELIN
2014-05-16 15:32 ` Maxime COQUELIN
2014-06-02 16:31 ` Wolfram Sang
2014-06-03  7:32   ` Maxime Coquelin
2014-06-03  7:32     ` Maxime Coquelin
     [not found]     ` <538D7A1C.5040409-qxv4g6HH51o@public.gmane.org>
2014-06-03  7:59       ` Wolfram Sang
2014-06-03  7:59         ` Wolfram Sang
2014-07-21 11:05         ` Maxime Coquelin
2014-07-21 11:05           ` Maxime Coquelin
     [not found]           ` <53CCF3EC.6030904-qxv4g6HH51o@public.gmane.org>
2014-07-21 14:03             ` Wolfram Sang [this message]
2014-07-21 14:03               ` 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=20140721140309.GA2734@katana \
    --to=wsa-z923lk4zbo2bacvfa/9k2g@public.gmane.org \
    --cc=kernel-F5mvAk5X5gdBDgjK7y7TUQ@public.gmane.org \
    --cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=maxime.coquelin-qxv4g6HH51o@public.gmane.org \
    --cc=patrice.chotard-qxv4g6HH51o@public.gmane.org \
    --cc=srinivas.kandagatla-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.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.