From: Ben Dooks <ben-i2c-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org>
To: Mark Brown
<broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>,
Linux I2C <linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH 2/2] i2c-algo-bit: Complain about masters which can't read SCL
Date: Tue, 7 Dec 2010 12:30:11 +0000 [thread overview]
Message-ID: <20101207123011.GO20097@trinity.fluff.org> (raw)
In-Reply-To: <20101207121009.GD10722-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
On Tue, Dec 07, 2010 at 12:10:10PM +0000, Mark Brown wrote:
> On Tue, Dec 07, 2010 at 11:07:05AM +0100, Jean Delvare wrote:
> > The I2C specification explicitly describes both SDA and SCL as
> > bidirectional lines. An I2C master with a read-only SCL is thus not
> > compliant. If a slow slave stretches the clock, errors will happen,
> > so the bus can't be considered as reliable.
> >
> > Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
>
> It'd be good to also flag this via sysfs so that it's more readily
> visible to things like diagnostic tools.
Could be, I wonder how many other hardware based adapters just don't
do this. Quite a few devices i've seen don't use it as they're generally
fast enough, or implement some other status polling system.
--
Ben
Q: What's a light-year?
A: One-third less calories than a regular year.
next prev parent reply other threads:[~2010-12-07 12:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-07 10:07 [PATCH 2/2] i2c-algo-bit: Complain about masters which can't read SCL Jean Delvare
[not found] ` <20101207110705.69792a1a-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2010-12-07 11:53 ` Ben Dooks
[not found] ` <20101207115325.GN20097-SMNkleLxa3Z6Wcw2j4pizdi2O/JbrIOy@public.gmane.org>
2010-12-07 15:07 ` Jean Delvare
[not found] ` <20101207160739.0d7141f3-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2010-12-08 4:01 ` Ben Dooks
2010-12-07 12:10 ` Mark Brown
[not found] ` <20101207121009.GD10722-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2010-12-07 12:30 ` Ben Dooks [this message]
[not found] ` <20101207123011.GO20097-SMNkleLxa3Z6Wcw2j4pizdi2O/JbrIOy@public.gmane.org>
2010-12-07 15:29 ` Jean Delvare
[not found] ` <20101207162933.3ad206a8-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org>
2010-12-07 15:35 ` Mark Brown
2010-12-08 4:03 ` Ben Dooks
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