[PATCH 12/12] i2c: pxa: enable/disable i2c module across msg xfer

Vaibhav Hiremath vaibhav.hiremath at linaro.org
Tue Jun 2 09:59:23 PDT 2015

On Tuesday 02 June 2015 10:22 PM, Vaibhav Hiremath wrote:
> On Thursday 28 May 2015 06:53 PM, Russell King - ARM Linux wrote:
>> On Thu, May 28, 2015 at 06:33:44PM +0530, Vaibhav Hiremath wrote:
>>> From: Yi Zhang <yizhang at marvell.com>
>>> Enable i2c module/unit before transmission and disable when it finishes.
>>> why?
>>> It's because the i2c bus may be distrubed if the slave device,
>>> typically a touch, powers on.
>> "disturbed"
>> I'd recommend that this is a DT property - not every platform is going to
>> want this, and as there is rudimentary I2C slave support in this driver,
>> this change breaks that.
> I would take it as two different comments here, and I believe you also
> meant same,
> 1. Not breaking I2C slave support
> Not sure whether enabling/disabling module in ISR would suffice here.
> To be specific, in the functions i2c_pxa_slave_start() &
> i2c_pxa_slave_stop()

Please ignore this option, as enable is important to generate interrupt
on slave start.

I will add DT property with clear note on SLAVE support issue, so that
it can be disabled and SLAVE support should work as is.


More information about the linux-arm-kernel mailing list