Re: rcar-i2c: always reads a byte

[Wolfram Sang <wsa@the-dreams.de>]

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> >>>The system issues an address transaction followed by a single byte
> >>>read.
> >>
> >>This fits to my observation that the rcar driver cannot do SMBUS_QUICK
> >>(e.g. via i2cdetect). I assumed that handling a length of 0 is broken. I
> >>haven't had a deeper look yet, so I can't say much. So, you either go
> >>for it yourself, or you wait until I posted my IIC enablement series for
> >>Lager. Then, you can switch to the IIC core with the sh_mobile driver.
> >>That one does SMBUS_QUICK correctly.
> >
> >I'll have a deeper look into this, I think there may be a solution.
> 
> I've tried issuing the ESG + FSB  bits as a command, however that
> did not work.

So, I experimented today as well. I don't think it is possible to have
zero-length support. I'll cook up a patch to disable them. Come to think
of it, it should be even for stable since I assume SMBUS_QUICK_WRITE
will also put a byte on the bus. Not good! And I2C_M_NOSTART is also out
of the question with this hardware.


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