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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





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
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux GPIO]     [Linux SPI]     [Linux Hardward Monitoring]     [LM Sensors]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux