linux-kernel - Re: [RFT PATCH] regmap-i2c: Only use I2C_FUNC_I2C if val

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Message-ID: <576E9EB8.4080100@roeck-us.net>
Date:	Sat, 25 Jun 2016 08:09:44 -0700
From:	Guenter Roeck <linux@...ck-us.net>
To:	Mark Brown <broonie@...nel.org>
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	linux-kernel@...r.kernel.org, Nishanth Menon <nm@...com>
Subject: Re: [RFT PATCH] regmap-i2c: Only use I2C_FUNC_I2C if val_bits == 8

On 06/25/2016 04:34 AM, Mark Brown wrote:
> On Fri, Jun 24, 2016 at 07:53:53PM -0700, Guenter Roeck wrote:
>
>> On chips with a register value size of 16 bits, I2C block reads will
>> typically not return the expected values. Instead, returned values
>> are most likely undefined if an operation crosses a register boundary.
>
> No, this just isn't true in general - if a device has trouble with bulk
> reads it needs to set use_sigle_rw in the config to disable them.
> Device limitations with bulk reads are a per device thing and are
> orthogonal to the value size, being more to do with the age and quality
> of the register map implementation than anything else.
>

Ok, thanks for letting me know. I'll try that.

Guenter