linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: "Grant Likely" <grant.likely@secretlab.ca>
To: "Domen Puncer" <domen.puncer@telargo.com>
Cc: khali@linux-fr.org, i2c@lm-sensors.org, linuxppc-embedded@ozlabs.org
Subject: Re: [PATCH] i2c-mpc: work around missing-9th-clock-pulse bug
Date: Mon, 9 Jul 2007 09:53:07 -0600	[thread overview]
Message-ID: <fa686aa40707090853j6079b0c7rbcff7c449baa15e0@mail.gmail.com> (raw)
In-Reply-To: <20070709071955.GD4186@moe.telargo.com>

On 7/9/07, Domen Puncer <domen.puncer@telargo.com> wrote:
> Work around a problem reported on:
> http://ozlabs.org/pipermail/linuxppc-embedded/2005-July/019038.html
> Without this patch I2C on mpc5200 becomes unusable after a while.
> Tested on mpc5200 based boards by Matthias and me.
>
> Index: work-powerpc.git/drivers/i2c/busses/i2c-mpc.c
> ===================================================================
> --- work-powerpc.git.orig/drivers/i2c/busses/i2c-mpc.c
> +++ work-powerpc.git/drivers/i2c/busses/i2c-mpc.c
> @@ -153,6 +167,9 @@ static void mpc_i2c_start(struct mpc_i2c
>  static void mpc_i2c_stop(struct mpc_i2c *i2c)
>  {
>         writeccr(i2c, CCR_MEN);
> +       mb();
> +       writeccr(i2c, 0);
> +       mb();
>  }

Are the mb() calls necessary?  The writeccr path includes eieio; is
that not sufficient?

Cheers,
g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
grant.likely@secretlab.ca
(403) 399-0195

  reply	other threads:[~2007-07-09 15:53 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-07-09  7:19 [PATCH] i2c-mpc: work around missing-9th-clock-pulse bug Domen Puncer
2007-07-09 15:53 ` Grant Likely [this message]
2007-07-10  6:17   ` Domen Puncer
2007-07-10  6:22     ` Grant Likely
2007-07-10 12:40       ` Jean Delvare
2007-07-11  5:49         ` Domen Puncer
2007-07-11  6:03           ` Grant Likely
2007-07-11  6:33             ` Domen Puncer
2007-07-11 11:40               ` Jean Delvare
2007-07-21  0:03 ` [i2c] " Guennadi Liakhovetski
2007-07-24  5:14   ` [PATCH] i2c-mpc: don't disable I2C module on stop condition Domen Puncer
2007-08-08 17:19     ` Jean Delvare
2007-08-08 18:33       ` Guennadi Liakhovetski

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=fa686aa40707090853j6079b0c7rbcff7c449baa15e0@mail.gmail.com \
    --to=grant.likely@secretlab.ca \
    --cc=domen.puncer@telargo.com \
    --cc=i2c@lm-sensors.org \
    --cc=khali@linux-fr.org \
    --cc=linuxppc-embedded@ozlabs.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).