Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756928Ab1CIJhr (ORCPT ); Wed, 9 Mar 2011 04:37:47 -0500 Received: from ch-smtp01.sth.basefarm.net ([80.76.149.212]:57048 "EHLO ch-smtp01.sth.basefarm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756745Ab1CIJho (ORCPT ); Wed, 9 Mar 2011 04:37:44 -0500 From: "Henrik Rydberg" Date: Wed, 9 Mar 2011 10:38:09 +0100 To: Benjamin Tissoires Cc: Dmitry Torokhov , Jiri Kosina , Stephane Chatty , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/4] hid-multitouch: Auto detection of maxcontacts Message-ID: <20110309093809.GA3980@polaris.bitmath.org> References: <1299601979-4871-1-git-send-email-benjamin.tissoires@enac.fr> <1299601979-4871-2-git-send-email-benjamin.tissoires@enac.fr> <20110309084222.GA3569@polaris.bitmath.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Originating-IP: 83.254.52.20 X-Scan-Result: No virus found in message 1PxFnh-0004pt-51. X-Scan-Signature: ch-smtp01.sth.basefarm.net 1PxFnh-0004pt-51 436a8f427dc304fff966adbbb1f2fb19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1916 Lines: 46 On Wed, Mar 09, 2011 at 10:03:45AM +0100, Benjamin Tissoires wrote: > On Wed, Mar 9, 2011 at 09:42, Henrik Rydberg wrote: > > Hi Benjamin, > > > >> This patch enables support of autodetection of maxcontacts. > >> We can still manually provide maxcontact in case the device > >> lies on it. > >> > >> Signed-off-by: Benjamin Tissoires > > > > It seems quite alright to let the classes contain the expected number > > of contacts, so I do not really see the reason for that part of the > > patch. How about keeping the maxcontacts in the class, and then do > > max(hid-provided-maxcontacts, default-maxcontacts)? > > > > Yep, I've got three particular reasons: > - 3M: there are two devices now, 1968 and 2256. The first one is a 10 > touches only, whereas the second one is a 60 touches. Right, so increasing the number of touches based on device information seems like a good idea. > - autodetection of multitouch devices. I have some patches on my tree > (that we do not want to go upstream right now for some reasons) that > allows us to plug any unknown multitouch devices and to let > hid-multitouch handling it. As most of the devices are 2 touches only, > and as the generic way to work with a multitouch devices is to iterate > over all the slots, using 10 touches by default infers a lot of > instructions that can be avoided. Right, so keeping the default number of touches per class seems like a good idea. > - finally, it simplifies the writing of the new CLS (we just need to > know how the device works to add the right quirks). Right, we always need to know how the device works. :-) Cheers, Henrik -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/