From: Michael Lawnick <ml.lawnick@gmx.de>
To: Mike Looijmans <mike.looijmans@topic.nl>
Cc: Wolfram Sang <wsa@the-dreams.de>,
linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i2c-mux-pca954x: Disable mux after 200ms timeout
Date: Mon, 25 Nov 2013 15:54:36 +0100 [thread overview]
Message-ID: <529364AC.8000305@gmx.de> (raw)
In-Reply-To: <1385387037-3710-1-git-send-email-mike.looijmans@topic.nl>
Hi,
Am 25.11.2013 14:43, schrieb Mike Looijmans:
> Leaving the mux enabled causes needless I2C traffic on the downstream
> bus. De-selecting after every request causes excess I2C traffic and
> switching.
>
> This patch implements a hybrid solution: After 200ms of inactivity,
> the mux is disabled.
...
Have you checked against behavior on cascaded muxes?
At least your desired timing will not look as expected.
200 ms: disable mux1
201 ms: enable mux1 - disable mux2
202 ms: enable mux2 - disable mux3
401 ms: disable mux1
402 ms: enable mux1 - disable mux2
602 ms: disable mux1
And on full second temperature sensor behind mux3 is read again ...
KR
Michael
next prev parent reply other threads:[~2013-11-25 14:54 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-25 13:43 [PATCH] i2c-mux-pca954x: Disable mux after 200ms timeout Mike Looijmans
2013-11-25 14:54 ` Michael Lawnick [this message]
2013-11-25 14:57 ` Wolfram Sang
-- strict thread matches above, loose matches on Subject: below --
2013-11-25 15:02 Mike Looijmans
2013-11-25 15:02 ` Mike Looijmans
2013-11-26 6:32 Mike Looijmans
2013-11-26 6:32 ` Mike Looijmans
[not found] ` <1385447520-3306-1-git-send-email-mike.looijmans-Oq418RWZeHk@public.gmane.org>
2013-11-26 9:06 ` Wolfram Sang
2013-11-26 9:06 ` Wolfram Sang
2013-11-26 9:36 ` Mike Looijmans
2013-11-26 9:36 ` Mike Looijmans
2013-11-26 12:28 ` Wolfram Sang
2013-11-26 13:39 ` Ulf Hansson
2013-11-26 13:39 ` Ulf Hansson
2013-11-26 14:06 ` Mike Looijmans
2013-11-26 14:06 ` Mike Looijmans
[not found] ` <5294AADC.5070707-Oq418RWZeHk@public.gmane.org>
2013-11-26 17:00 ` Wolfram Sang
2013-11-26 17:00 ` Wolfram Sang
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