Re: [PATCH v7 03/15] i2c: octeon: Remove I2C_FUNC_SMBUS_QUICK support

Jan Glauber
2016-04-26T12:35:03Z

On Tue, Apr 26, 2016 at 09:36:20AM +0200, Wolfram Sang wrote:
>
> > > Yes, I thought briefly about splitting SMBUS_QUICK into read-write
> > > variants too. To me the question is if this feature is still used on modern
> > > devices or if this is more a relict of the past. I don't know enough
> > > about SMBUS to answer that.
>
> Well, note that there are zero-length messages in I2C allowed as well.
> Not only in SMBUS. I mainly use the term SMBUS_QUICK because it covers
> both cases.
>
>
> > Checking on ThunderX:
> ...
> > Do all these other numbers make sense (although there are no
> > devices)?
>
> It makes sense in a way that it shows SMBUS_QUICK_WRITE is broken :) It
> doesn't react to ACK/NACK properly. So, what needs to be done:
>
> 1) remove SMBUS_QUICK as you did in this patch 2) move the length check
> so it doesn't only check read messages but also write messages. That is
> to prevent handling custom setup I2C messages with a length of 0 (which
> is legal). I'd suggest to return -EOPNOTSUPP in this case.

OK, I'll do that. Should I rebase the remaining patches or would you
like to review them first ? :)

Thanks,
Jan

> Thanks,
>
> Wolfram
>