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From: Robert Schwebel <robert-xKSCrvTH0lQb1SvskN2V4Q@public.gmane.org>
To: Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>
Cc: "Wolfram Sang" <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>,
	"Fabio Estevam"
	<fabio.estevam-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
	"Wolfgang Denk" <wd-ynQEQJNshbs@public.gmane.org>,
	"Detlev Zundel" <dzu-ynQEQJNshbs@public.gmane.org>,
	"Stefano Babic" <sbabic-ynQEQJNshbs@public.gmane.org>,
	"Sascha Hauer" <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>,
	linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	"Uwe Kleine-König"
	<u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>,
	"Shawn Guo" <shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
	"Dong Aisheng" <b29396-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
	"Linux ARM kernel"
	<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>
Subject: Re: [PATCH 1/2 V2] MXS: Set I2C timing registers for mxs-i2c
Date: Tue, 10 Jul 2012 16:09:11 +0200	[thread overview]
Message-ID: <20120710140911.GK20456@pengutronix.de> (raw)
In-Reply-To: <201207091758.22788.marex-ynQEQJNshbs@public.gmane.org>

On Mon, Jul 09, 2012 at 05:58:22PM +0200, Marek Vasut wrote:
> > The kernel should work for all users, not only for the majority, so:
> > Better safe than sorry.
> >
> > Also, defaults should make the system work. Tuning can be done later by
> > somebody who understands what is needed.
> >
> > And frankly, this attitude which made you add a potential regression is
> > worrisome. I'd suggest to give stability a higher priority.
>
> I believe you misunderstood my intention. Setting it to 400kHz was done because
> it's what most people will use, therefore avoiding duplication (most of the
> board files will override this setting now). All right, your sane defaults here
> can be applied, I won't argue.

I think all I2C chips support 100 kHz, but only selected ones support
400 kHz.

rsc
-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

WARNING: multiple messages have this Message-ID (diff)
From: robert@schwebel.de (Robert Schwebel)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2 V2] MXS: Set I2C timing registers for mxs-i2c
Date: Tue, 10 Jul 2012 16:09:11 +0200	[thread overview]
Message-ID: <20120710140911.GK20456@pengutronix.de> (raw)
In-Reply-To: <201207091758.22788.marex@denx.de>

On Mon, Jul 09, 2012 at 05:58:22PM +0200, Marek Vasut wrote:
> > The kernel should work for all users, not only for the majority, so:
> > Better safe than sorry.
> >
> > Also, defaults should make the system work. Tuning can be done later by
> > somebody who understands what is needed.
> >
> > And frankly, this attitude which made you add a potential regression is
> > worrisome. I'd suggest to give stability a higher priority.
>
> I believe you misunderstood my intention. Setting it to 400kHz was done because
> it's what most people will use, therefore avoiding duplication (most of the
> board files will override this setting now). All right, your sane defaults here
> can be applied, I won't argue.

I think all I2C chips support 100 kHz, but only selected ones support
400 kHz.

rsc
-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

  parent reply	other threads:[~2012-07-10 14:09 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-06  6:09 [PATCH 1/2 V2] MXS: Set I2C timing registers for mxs-i2c Marek Vasut
2012-07-06  6:09 ` Marek Vasut
     [not found] ` <1341554956-17416-1-git-send-email-marex-ynQEQJNshbs@public.gmane.org>
2012-07-06  6:09   ` [PATCH 2/2 V2] MXS: Implement DMA support into mxs-i2c Marek Vasut
2012-07-06  6:09     ` Marek Vasut
2012-07-09 10:53   ` [PATCH 1/2 V2] MXS: Set I2C timing registers for mxs-i2c Wolfram Sang
2012-07-09 10:53     ` Wolfram Sang
     [not found]     ` <20120709105338.GE1296-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-07-09 11:07       ` Marek Vasut
2012-07-09 11:07         ` Marek Vasut
     [not found]         ` <201207091307.35860.marex-ynQEQJNshbs@public.gmane.org>
2012-07-09 12:05           ` Wolfram Sang
2012-07-09 12:05             ` Wolfram Sang
     [not found]             ` <20120709120523.GG1296-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-07-09 15:58               ` Marek Vasut
2012-07-09 15:58                 ` Marek Vasut
     [not found]                 ` <201207091758.22788.marex-ynQEQJNshbs@public.gmane.org>
2012-07-10 14:09                   ` Robert Schwebel [this message]
2012-07-10 14:09                     ` Robert Schwebel
     [not found]                     ` <20120710140911.GK20456-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-07-10 15:13                       ` Marek Vasut
2012-07-10 15:13                         ` Marek Vasut
  -- strict thread matches above, loose matches on Subject: below --
2012-06-08 18:54 Marek Vasut
2012-06-08 18:54 ` Marek Vasut
     [not found] ` <1339181689-22573-1-git-send-email-marex-ynQEQJNshbs@public.gmane.org>
2012-06-09  4:15   ` Shubhrajyoti Datta
2012-06-09  4:15     ` Shubhrajyoti Datta
     [not found]     ` <CAM=Q2cuv0NQTYJH=+d6Na+JK5rGYsLiSmuX7g8T-_Ry7bs3fRQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-06-09 10:34       ` Marek Vasut
2012-06-09 10:34         ` Marek Vasut
     [not found]         ` <201206091234.47309.marex-ynQEQJNshbs@public.gmane.org>
2012-06-09 10:53           ` Sascha Hauer
2012-06-09 10:53             ` Sascha Hauer
     [not found]             ` <20120609105330.GF30400-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-06-09 11:11               ` Marek Vasut
2012-06-09 11:11                 ` Marek Vasut
     [not found]                 ` <201206091311.43229.marex-ynQEQJNshbs@public.gmane.org>
2012-06-09 11:25                   ` Sascha Hauer
2012-06-09 11:25                     ` Sascha Hauer
     [not found]                     ` <20120609112545.GH30400-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-06-09 11:40                       ` Marek Vasut
2012-06-09 11:40                         ` Marek Vasut
2012-06-09 12:46           ` Shubhrajyoti Datta
2012-06-09 12:46             ` Shubhrajyoti Datta
     [not found]             ` <CAM=Q2cvvwXimLY358ET69U6qCsGoxenYMNtApYbhpn4cCC0nUg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-06-09 13:10               ` Marek Vasut
2012-06-09 13:10                 ` Marek Vasut

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