Re: [PATCH-v3 07/11] i2c: pxa: enable/disable i2c module across msg xfer

[Vaibhav Hiremath]

On Friday 10 July 2015 01:54 PM, Wolfram Sang wrote:
> On Tue, Jul 07, 2015 at 12:54:51AM +0530, Vaibhav Hiremath wrote:
> > From: Yi Zhang <yizhang@xxxxxxxxxxx>
> >
> > 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.
> >
> > As we do not want to break slave mode support, this patch introduces
> > DT property to control disable of the I2C module after xfer in master mode
> > of operation.
> >
> > i2c-disable-after-xfer : If set, driver will disable I2C module after msg xfer
>
> Hmm, I am not sure this property fits into the "describing hardware"
> category. And we can't make the below behaviour default, because the
> udelay(100) will cause quite some latency.
>
> >

Sorry for delayed response,
I thought I responded to this, but when I was preparing for V4,
realized it that I did not :)

Yes, I agree that, this doesn't look like HW description. But I could
not find any other mechanism to handle this.
And also during V1 discussion, I did not get any objection to this
approach.


Thanks,
Vaibhav
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