* question about i2c-designware
@ 2015-07-09 8:59 Kefeng Wang
2015-07-10 4:11 ` Kefeng Wang
0 siblings, 1 reply; 3+ messages in thread
From: Kefeng Wang @ 2015-07-09 8:59 UTC (permalink / raw
To: linux-i2c-u79uwXL29TY76Z2rM5mHXA
Cc: Wolfram Sang, Alexey Brodkin, Ding Tianhong,
Guohanjun (Hanjun Guo)
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
^ permalink raw reply [flat|nested] 3+ messages in thread
* question about i2c-designware
@ 2015-07-10 4:11 ` Kefeng Wang
0 siblings, 0 replies; 3+ messages in thread
From: Kefeng Wang @ 2015-07-10 4:11 UTC (permalink / raw
To: linux-arm-kernel
+ linux-arm-kernel at lists.infradead.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
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: question about i2c-designware
@ 2015-07-10 4:11 ` Kefeng Wang
0 siblings, 0 replies; 3+ messages in thread
From: Kefeng Wang @ 2015-07-10 4:11 UTC (permalink / raw
To: linux-i2c-u79uwXL29TY76Z2rM5mHXA
Cc: Wolfram Sang, Alexey Brodkin, Ding Tianhong,
Guohanjun (Hanjun Guo),
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@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
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-07-10 4:11 ` Kefeng Wang
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