On Thu, May 27, 2010 at 12:03 AM, Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote: > On Wed, May 26, 2010 at 08:59:35AM -0700, Ping Cheng wrote: >> On Tue, May 25, 2010 at 1:23 PM, Dmitry Torokhov >> <dmitry.torokhov@xxxxxxxxx> wrote: >> > On Tue, May 25, 2010 at 09:52:29PM +0200, Henrik Rydberg wrote: >> >> Dmitry Torokhov wrote: >> >> > Hi Henrik, >> >> > >> >> > On Tue, May 25, 2010 at 01:52:57PM +0200, Henrik Rydberg wrote: >> >> >> These patches are in response to the discussion about input state >> >> >> retrieval. >> >> >> >> >> >> The current EVIOCGABS method does not work with MT slots. These >> >> >> patches provides a mechanism where a slot is first selected via a call >> >> >> to EVIOCSABS, after which the corresponding MT events can be extracted >> >> >> with calls to EVIOCGABS. >> >> >> >> >> >> The symmetric operation, to set the MT state via EVIOCSABS, seems to >> >> >> violate input data integrity, and is therefore not implemented. >> >> >> >> >> > >> >> > This looks sane, however the question remains - is there any users for >> >> > this data? Like I mentioned, I can see the need to fetch state of >> >> > switches and ranges of absolute axis, and even non-multitouch ABS values >> >> > (due to the fact that some input devices, like sliders, may stay in a >> >> > certain position for long periods of time), but I expect multitouch data >> >> > to be "refreshed" very quickly. >> >> > >> >> > Thanks. >> >> > >> >> >> >> There were some voices addressing this issue, and the patches are here, >> >> available for whomever to pick up. Drop them if you wish, I will not send them anew. >> >> >> > >> > I'll save them in my queue but will hold off applying until I hear >> > userspace folks requesting such functionality. >> >> Hi Dmitry, >> >> You do have a valid point - the (x,y) from a touch object would most >> likely change all the time. Even if the object itself is in a steady >> state on the digitizer, i.e., without any intentional movement, the >> electronic noise would most likely lead to some (x,y) changes. So, the >> chance that we need to retrieve (x,y) is rare. >> >> However, it is possibe that when X driver starts, an object was >> already on the digitizer. And the digitizer is of such a high quality >> :), it filtered all the noises so we can not locate the touch without >> a EVIOCGABS call. >> >> Plus, from a pure coding/development point of view, it is not a bad >> practice to provide the equivalent features for _MT_ support as we did >> for the existing input devices. At least, it doesn't hurt to make the >> support consistent across devices/tools (considering touch as a new >> input device/tool). > > Ping, > > I did not say that there was a problem with the patch, I agree with it. > However if no one using this - why should we bother? Will _you_ utilize > this functionality in Wacom X driver? If so let me know and I will merge > it. tbh, I can not say that I will need it in my X driver for sure. But I vote for it to be merged. Thank you for placing me in such an important position :). Ping -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
