From: Kefeng Wang <wangkefeng.wang-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
To: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>,
Alexey Brodkin <abrodkin-HKixBCOQz3hWk0Htik3J/w@public.gmane.org>,
Ding Tianhong
<dingtianhong-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
"Guohanjun (Hanjun Guo)"
<guohanjun-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
"linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org"
<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>
Subject: Re: question about i2c-designware
Date: Fri, 10 Jul 2015 12:11:38 +0800 [thread overview]
Message-ID: <559F45FA.8060801@huawei.com> (raw)
In-Reply-To: <559E37D7.6040103-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
+ linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
On 2015-07-09 16:59, Kefeng Wang wrote:
> Hi all,
>
> We met a issue when use Synopsys DesignWare I2C. The SDA will keep low level and never go back to the high level
> if both i2c controllers simultaneously access the same i2c device(rtc), then both two i2c controllers can't send any data.
> we try to reset the rtc, but not working. After reset the i2c controller, the SDA goes back to the high state and we
> can get time from rtc again.
>
> The scenario is as follows, any advice will be appreciated.
>
> OS 1 | OS 2
> |
> +--------------+----------|--------------+
> | | | |
> | +---------|----+-----|---------+ |
> | | | | | | |
> ---------------- ------ | -----------------
> |i2c controller1| | rtc| | |i2c controller2|
> ---------------- ------ | -----------------
> |
> note:
> 1) i2c controller1 and controller2 use same IP.
> 2) OS1 use v3.19 and OS2 use 2.6
>
> Thanks
> Kefeng
>
prev parent reply other threads:[~2015-07-10 4:11 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-09 8:59 question about i2c-designware Kefeng Wang
[not found] ` <559E37D7.6040103-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2015-07-10 4:11 ` Kefeng Wang [this message]
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