Re: rcar-i2c: always reads a byte

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

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On Tue, Mar 11, 2014 at 04:15:02PM +0000, Ben Dooks wrote:
> I have noticed the following behaviour with the i2c-rcar driver
> with the following single i2c_msg structure:
> 
> 	msg[0].addr = 0x12;
> 	msg[0].flags = I2C_M_RD;
> 	msg[0].len = 0;
> 	msg[0].buf = data;
> 
> 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.

Regards,

   Wolfram


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