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From: ludovic.desroches@atmel•com (ludovic.desroches)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] i2c: at91: add a sanity check on i2c message length
Date: Fri, 2 Nov 2012 17:00:43 +0100	[thread overview]
Message-ID: <5093EE2B.8080005@atmel.com> (raw)
In-Reply-To: <20121102111432.GD21313@pengutronix.de>

Le 11/02/2012 12:14 PM, Wolfram Sang a ?crit :
> On Fri, Nov 02, 2012 at 12:04:45PM +0100, ludovic.desroches wrote:
>> Hi Wolfram,
>>
>> Le 11/01/2012 11:29 PM, Wolfram Sang a ?crit :
>>> On Wed, Oct 10, 2012 at 04:25:58PM +0200, ludovic.desroches at atmel.com wrote:
>>>> From: Ludovic Desroches <ludovic.desroches@atmel•com>
>>>>
>>>> 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 <ludovic.desroches@atmel•com>
>>>
>>> What happens if you send a 0 byte message? Some hardware is able to do
>>> 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?

Thanks

Regards

Ludovic

next prev parent reply	other threads:[~2012-11-02 16:00 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-10 14:25 [PATCH] i2c: at91: add a sanity check on i2c message length ludovic.desroches at atmel.com
2012-10-24 14:34 ` ludovic.desroches
2012-11-01 22:29 ` Wolfram Sang
2012-11-02 11:04   ` ludovic.desroches
2012-11-02 11:14     ` Wolfram Sang
2012-11-02 16:00       ` ludovic.desroches [this message]
2012-11-03 14:16         ` Wolfram Sang
2012-11-05  6:08         ` Voss, Nikolaus

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