Re: [PATCH 4/4] i2c: xlp9xx: Check for Bus state after every transfer

From: George Cherian
Date: Tue Feb 27 2018 - 04:32:31 EST


Hi Wolfram,

On 02/27/2018 02:34 PM, Wolfram Sang wrote:
On Tue, Feb 27, 2018 at 10:30:31AM +0530, George Cherian wrote:
Hi Wolfram,

Thanks for the review.

On 02/27/2018 01:52 AM, Wolfram Sang wrote:

On Thu, Jan 18, 2018 at 05:39:24AM +0000, George Cherian wrote:
I2C bus enters the STOP condition after the DATA_DONE interrupt is raised.
Essentially the driver should be checking the bus state before sending
the next transaction.

Yes.

In case the next transaction is initiated while the
bus is busy, the prior transactions stop condition is not achieved.

I didn't fully get why you can't check the BUSY bit and wait a little
just before you push out the next message?
Yes, I am checking for the BUSY bit and looping.

Yes, but *after* the STOP, not *before* the next message. I haven't
fully understood why you don't do this before the next message is about
to be sent. That might save you some busy looping, or?
Yes, Thanks for the clarification. You are right It is better to
check before next message. I will make required changes and post the patch.


Regards
-George