From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH] i2c/busses: Driver for Devantech USB-ISS I2C adapter Date: Tue, 22 Mar 2011 21:50:58 -0700 Message-ID: <20110323045058.GA13606@kroah.com> References: <1300851827-13627-1-git-send-email-guenter.roeck@ericsson.com> <20110323034524.GA11675@kroah.com> <20110323042507.GA9173@ericsson.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20110323042507.GA9173@ericsson.com> Sender: linux-doc-owner@vger.kernel.org To: Guenter Roeck Cc: Jean Delvare , Ben Dooks , Randy Dunlap , "linux-i2c@vger.kernel.org" , "linux-usb@vger.kernel.org" , "linux-doc@vger.kernel.org" List-Id: linux-i2c@vger.kernel.org On Tue, Mar 22, 2011 at 09:25:07PM -0700, Guenter Roeck wrote: > On Tue, Mar 22, 2011 at 11:45:24PM -0400, Greg KH wrote: > > On Tue, Mar 22, 2011 at 08:43:47PM -0700, Guenter Roeck wrote: > > > This patch adds support for the I2C interface of the Devantech USB-ISS > > > Multifunction adapter. > > > > > > Signed-off-by: Guenter Roeck > > > --- > > > The driver has one problem: It competes with the cdc_acm driver for device > > > access. Copying the usb mailing list in the hope that someone can tell me > > > if there is a way to prevent this from happening. > > > > Why does it "compete"? > > Is it because this driver also exposes a cdc-acm class interface? Why > > I guess so. > > > is it doing that if it doesn't follow that spec? We do already support > > I don't know if it follows the cdc-acm specification or not, though I would > think it does since the cdc-acm driver recognizes it. I do see the > "This device cannot do calls on its own. It is not a modem." message. > > I suspect the device exposes the cdc-acm class interface because it is > a convenient means to make it show up as COM port in Windows. > But I am not associated with the manufacturer, so that is just a wild guess. > > If it does follow the cdc-acm specification, does that help me anything ? It should, you can talk to the device from userspace using that virtual serial port, right? Isn't that what you need to do here? Why try to create a new type of interface to the device from what it was supposed to be by the manufacturer? thanks, greg k-h