From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH v9 1/8] drivers:input:tsc2007: add new common binding names, pre-calibration, flipping and rotation Date: Sun, 19 Feb 2017 20:05:47 +0100 Message-ID: <20170219190547.GA17292@amd> References: <20170218091526.GC8937@amd> <61F3C580-4BF2-4EE6-9DEC-FB8634434EC0@goldelico.com> <20170218180811.GB9377@amd> <27287BC5-E4E2-4F50-B140-C74D3CADED5B@goldelico.com> <20170218225435.GA4693@amd> <20170219141715.GA7159@amd> <05F3816F-46E6-4BC2-9E2E-F20E645F7197@goldelico.com> <20170219171518.GA12833@amd> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="3V7upXqbjpZ4EhLz" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-input-owner@vger.kernel.org To: "H. Nikolaus Schaller" Cc: Dmitry Torokhov , Sebastian Reichel , Mark Rutland , =?iso-8859-1?Q?Beno=EEt?= Cousson , Tony Lindgren , Russell King , Arnd Bergmann , Michael Welling , Mika =?iso-8859-1?Q?Penttil=E4?= , Javier Martinez Canillas , Igor Grinberg , "Andrew F. Davis" , Mark Brown , Jonathan Cameron , Rob Herring , Alexander Stein , Eric Engestrom , Hans de Goede Benjamin Tissoires List-Id: devicetree@vger.kernel.org --3V7upXqbjpZ4EhLz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > Hi Pavel, > I love discussions with you :) Unfortunately I can't say the same. > > Am 19.02.2017 um 18:15 schrieb Pavel Machek : > >=20 > >=20 > >>> Solve it properly. That means passing calibration > >>> data from kernel to userland. > >>=20 > >> As written before, the really proper solution would be to provide floa= ting > >> or fixed point subpixel input events. Not arbitrarily scaling up in ke= rnel > >> and leaving downscaling to user space (where everybody can make it > >> worse). > >=20 > > That has no advantages, >=20 > It has the advantage of providing you with the full precision of raw data= (but > properly scaled) so that you don't loose any bit of information. This is = what > you just asked for - one or two mails before. Not really, right? No matter what kind of fixed point you introduce, you'll still loose precision. > > and floating point in kernel is hard. Also > > you'd either have to invent new interface, or you'd break touchscreen > > for people that already have their touchscreens calibrated. >=20 > No, I don't break calibration for people using a different chip. So you propose your touchscreen to behave differently from all other touchscreens in tree? That's just no-go. > > Yes, that's not really proper solution, that just overengineered. Not > > worth implementing. Pass calibration data to userland. >=20 > You seem to repeat yourself and just say which solution you prefer, > but I am missing the arguments why your solution (Pass calibration data > to userland) is right and the best one. > Which problems does it solve? All you described. > Which one does it solve better than others? It is not terminally ugly. > How can you implement it in > a stable and portable way? Easily. > How can you make sure that all user-space GUI > systems can and will make use of this calibration data? You can't, and you don't need to. Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --3V7upXqbjpZ4EhLz Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlip7IsACgkQMOfwapXb+vJz1ACbBm1XiEklbcPpEKAifUTzqcpl C7IAnimyfkFxjDaJFywe9TTgBzkYsL1v =XerP -----END PGP SIGNATURE----- --3V7upXqbjpZ4EhLz--