From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hutterer Subject: Re: [RFC v2] input: Introduce device information ioctl Date: Mon, 20 Dec 2010 18:16:42 +1000 Message-ID: <20101220081642.GA17764@barra.redhat.com> References: <1292440807-18502-1-git-send-email-rydberg@euromail.se> <20101216002941.GC4952@salty.local> <20101216004358.GA22066@core.coreip.homeip.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20101216004358.GA22066@core.coreip.homeip.net> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Torokhov Cc: Henrik Rydberg , Jiri Kosina , Ping Cheng , Chris Bagwell , Chase Douglas , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-input@vger.kernel.org [sorry, mail stuck in my outbox for some reason] On Wed, Dec 15, 2010 at 04:43:58PM -0800, Dmitry Torokhov wrote: > On Thu, Dec 16, 2010 at 10:29:42AM +1000, Peter Hutterer wrote: > > > > > > /* > > > + * Device properties and quirks > > > + */ > > > + > > > +#define INPUT_PROP_POINTER 0x00 /* needs a pointer */ > > > +#define INPUT_PROP_DIRECT 0x01 /* direct object manipulation */ > > > > fwiw, I think the common term for these is "direct input devices", at least > > that's how a lot of the research literature refers to them. Might be good to > > use the same term. > > > > either way, not sure about this one. I've worked with devices that were > > indirect by nature but used directly. e.g. the magic touchpad could quite > > easily be used as direct input device with an top-down projector. the > > decision to use it as an indirect device is a UI decision. > > Likewise, some mountable direct-touch touchscreens can be used indirectly if > > the touchscreen isn't mounted straight on the display. This is very much a > > setup-specific property and I'm not sure about the value of this > > information. > > All of these "props" would have no reflection on the event stream > generated by the device, and exist solely for the benefits of userspace > consumers to help them set up the device automatically and interpret the > data appropriately. As such, if someone uses touchscreen as a tablet, I > believe userspace should allow it, but at the price of manual setup. > > If we start seeing cuch devices we could consider EVIOCSPROPS so > infrastructure (udev) could adjust the properties so that upper levels > (X) can still use the data to set up devices properly. > > What do you think? I figured it didn't have any effect on the data stream. I think that for 95% of the devices, this information will probably be correct and the only ones affected are rather exotic setups anyway that need special setup. so I don't really oppose the flag, but there should be documentation on what it means and that it only represents the assumed usage of the device. Cheers, Peter