ludovic.desroches wrote on Friday, November 02, 2012 5:01 PM:

Le 11/02/2012 12:14 PM, Wolfram Sang a ?crit :

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On Fri, Nov 02, 2012 at 12:04:45PM +0100, ludovic.desroches wrote:

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Hi Wolfram,

Le 11/01/2012 11:29 PM, Wolfram Sang a ?crit :

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On Wed, Oct 10, 2012 at 04:25:58PM +0200,

ludovic.desroches at atmel.com wrote:

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From: Ludovic Desroches <redacted>

If the i2c message length is zero, i2c-at91 will directly return an error
instead of trying to send a zero-length message.

Signed-off-by: Ludovic Desroches <redacted>

What happens if you send a 0 byte message? Some hardware is able to

do

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this and it will be used in SMBUS QUICK which the driver states to
support according to at91_twi_func().

Without this I had some data corruption when writing to / reading
from a serial eeprom (depending on the IP version).

Yes SMBUS quick command is supported but is not managed in the
driver, we have to tell explicitly the IP that we want to send this
command.

Ok, so unless you want to implement the support, please update this
patch with a comment that SMBUS_QUICK is a TODO and remove the
SMBUS_QUICK capability.

Implementation should not be a huge task, only one bit to set in a
register but I have no device to test it.
So I will choose to remove the SMBUS_QUICK capability.

Hi Nikolaus,

Did you test the driver with SMBus compatible devices? Can I keep other
SMBus capabilities from SMBUS_EMUL?

Hi Ludovic,

yes, I use this driver with the sbs driver to query a smbus-attached
battery with a TI bq chip (I actually wrote this driver only for this
purpose). I implemented and tested SMBUS_BLOCK but not
SMBUS_QUICK...

Niko