[PATCH-v3 02/11] i2c: pxa: No need to set slave addr for i2c master mode reset

Vaibhav Hiremath vaibhav.hiremath at linaro.org
Mon Jul 13 00:09:53 PDT 2015

On Friday 10 July 2015 08:26 PM, Wolfram Sang wrote:
> On Fri, Jul 10, 2015 at 07:55:31PM +0530, Vaibhav Hiremath wrote:
>> On Friday 10 July 2015 07:44 PM, Wolfram Sang wrote:
>>> On Fri, Jul 10, 2015 at 06:08:43PM +0530, Vaibhav Hiremath wrote:
>>>> On Friday 10 July 2015 01:41 PM, Wolfram Sang wrote:
>>>>> On Tue, Jul 07, 2015 at 12:54:46AM +0530, Vaibhav Hiremath wrote:
>>>>>> Normally i2c controller works as master, so slave addr is not needed, or it
>>>>>> will impact some slave device (eg. ST NFC chip) i2c accesses, because it has
>>>>>> the same i2c address with controller.
>>>>> Just to make sure: Does it? As I read the code, slave interrupts are
>>>>> enabled later only when slave mode is selected? Is that a HW bug? And if
>>>>> so, can't the code just be moved into this #ifdef block later?
>>>> Yes we could, infact I thought about it;
>>>> but I would break recommended sequence here.
>>> And did you set the "own slave address" to a value which one of your
>>> existing i2c slaves also has (without enabling slave mode)? Did it
>>> disturb communication?
>> Since slave and master mode are mutual exclusive,
>> I did not try this.
> Ehrm, what I meant was. Did you see the issue mentioned in the above
> commit message? Can you reproduce it? You don't need to enable slave
> mode for that, no?

Ohh yes,

I am able to reproduce this issue.

I have pxa1928 based board, where I have only PMIC 88PM860 connected to
I2C bus, and whenever I set slave address to 0x30 (PMIC slave address)
all I2C transaction for PMIC goes for toss.


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