From: Wolfram Sang Subject: Re: I2C_M_RECV_LEN for i2c-mxs Date: Sun, 14 Apr 2013 13:57:58 +0200 Message-ID: <20130414115757.GA9013@the-dreams.de> References: <20130412093003.GE30416@pengutronix.de> <20130412153757.GA10241@the-dreams.de> <20130412182611.GG30416@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20130412182611.GG30416-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Uwe =?iso-8859-15?Q?Kleine-K=F6nig?= Cc: Marek Vasut , Wolfram Sang , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Hi Uwe, > The reason I used wolfram@... is probably: Looking up MAINTAINERS would have done it :) > Ah, ok. But then there is a different problem: Even though "my" driver > only advertises I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL calling > i2c_smbus_read_block_data in userspace results in .master_xfer being > called with I2C_M_RECV_LEN set. >From Documentation/i2c/functionality: Because not every I2C or SMBus adapter implements everything in the I2C specifications, a client can not trust that everything it needs is implemented when it is given the option to attach to an adapter: the client needs some way to check whether an adapter has the needed functionality... Regards, Wolfram