From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751768AbdBSMFx (ORCPT ); Sun, 19 Feb 2017 07:05:53 -0500 Received: from mo4-p04-ob.smtp.rzone.de ([81.169.146.178]:23083 "EHLO mo4-p04-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751405AbdBSMFu (ORCPT ); Sun, 19 Feb 2017 07:05:50 -0500 X-RZG-CLASS-ID: mo04 X-RZG-AUTH: :JGIXVUS7cutRB/49FwqZ7WcecEarQROEYabkiUo6mSAGQ+qKID8/PAQna8Y= Subject: Re: [PATCH v9 1/8] drivers:input:tsc2007: add new common binding names, pre-calibration, flipping and rotation Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Content-Type: multipart/signed; boundary="Apple-Mail=_396942DE-7251-42FE-AE9C-DA4B2AF1E5EF"; protocol="application/pgp-signature"; micalg=pgp-sha256 X-Pgp-Agent: GPGMail From: "H. Nikolaus Schaller" In-Reply-To: <20170218225435.GA4693@amd> Date: Sun, 19 Feb 2017 13:05:25 +0100 Cc: Dmitry Torokhov , Sebastian Reichel , Mark Rutland , =?utf-8?Q?Beno=C3=AEt_Cousson?= , Tony Lindgren , Russell King , Arnd Bergmann , Michael Welling , =?utf-8?Q?Mika_Penttil=C3=A4?= , Javier Martinez Canillas , Igor Grinberg , "Andrew F. Davis" , Mark Brown , Jonathan Cameron , Rob Herring , Alexander Stein , Eric Engestrom , Hans de Goede , Benjamin Tissoires , Petr Cvek , Mauro Carvalho Chehab , Hans Verkuil , Nick Dyer , Siebren Vroegindeweij , Michel Verlaan , linux-input@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, letux-kernel@openphoenux.org, linux-iio@vger.kernel.org, kernel@pyra-handheld.com, Aaro Koskinen , =?utf-8?Q?Pali_Roh=C3=A1r?= , Andrey Gelman , Haibo Chen Message-Id: References: <9830dd21e6425e3a866fac6ed4cc73ddd58b719f.1482936802.git.hns@goldelico.com> <20170128193342.GB38136@dtor-ws> <1F6355E1-A5E3-41A6-908F-619A15581BEF@goldelico.com> <20170217204041.GE13050@dtor-ws> <20170218091526.GC8937@amd> <61F3C580-4BF2-4EE6-9DEC-FB8634434EC0@goldelico.com> <20170218180811.GB9377@amd> <27287BC5-E4E2-4F50-B140-C74D3CADED5B@goldelico.com> <20170218225435.GA4693@amd> To: Pavel Machek X-Mailer: Apple Mail (2.3124) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Apple-Mail=_396942DE-7251-42FE-AE9C-DA4B2AF1E5EF Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Hi Pavel, > Am 18.02.2017 um 23:54 schrieb Pavel Machek : >=20 > On Sat 2017-02-18 20:17:09, H. Nikolaus Schaller wrote: >>=20 >>> Am 18.02.2017 um 19:08 schrieb Pavel Machek : >>>=20 >>>>> And I agree that kernel should _not_ attempt rescaling itself, as = it >>>>> would lose precision. >>>>=20 >>>> With an almost 1:1 mapping you won't loose precision. >>>=20 >>> How do you propose to do that? >>=20 >> something like >>=20 >> xinput --set-prop --type=3Dfloat "TSC200X touchscreen" "Coordinate = Transformation Matrix" 1.00 0.00 0.00 0.00 1.00 0.00 0.00 0.00 1.00 >>=20 >> but I think it is the default of X11 if you use no coordinate = transformation at all. >> And having the kernel to properly scale from ADC values to screen = coordinates. >>=20 >=20 > No. How do you propose doing rescaling in the kernel without loosing > precision? I wonder how it works with your setting xinput --set-prop --type=3Dfloat "TSC200X touchscreen" "Coordinate = Transformation Matrix" 1.10 0.00 -0.05 0.00 1.18 -0.10 0.00 0.00 1.00 This obviously also assumes that the input events report pixel = coordinates or you would have factors not close to 0.00 and 1.00. It just aligns the touch with the screen, i.e. calibrates. Or your = example was incomplete. About loosing precision: there is already noise (jitter) in real-world = devices so that you can't achieve subpixel precision anyways (unless = your panel has a very low resolution). Please see my answer to Dmitry = some mails ago. BR and thanks, Nikolaus --Apple-Mail=_396942DE-7251-42FE-AE9C-DA4B2AF1E5EF Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- iQIcBAEBCAAGBQJYqYoGAAoJEIl79TGLgAm6O+MP/2xCAvKRKen8ZX6ZylTNCgnz BJEp+awnsICgeb6Cny2vm29ujBMSyBKR7dgPjgGFLJV8C2jLlaPjPgKuOxKMYXdl iAi0yQoqwRR7rONWGd74aiWQHhpXmt8LSRD5trXrpA1aAC2qmpDyLeCKwkA5UskE EzcXMh125ZsrKUtk2qHJ3a/RMWbGIlvBdlw/A7qfkwF6FedyKL7GQMoE0iV/GVcK ynHhIzTH+3m3ajU2uZK0ZOIv/4AdNYLu+5mVmbaQt0bgSzEMBsmUW1pyx6fdqJKL tcYBiHCRx2pLwh6tju3GzCzmv0DJrWv+UDan2DqjMMRsVsA0qhY9k6QG4F2CG5+Y HkWxb4Je7AUAAz2kO3MMxGDErDEaqVJDajiBQLMSQDZTvJ1DOeOgHPKJUQ6pdpNF qkXrD+8Mw658dmTx2t8brYoVY51wvadCKkidhdWMCV71P0pP2hDraMYaJm4pUasY YMhkE8MG7dhaPY++sO0K0iJj7nEC/UNMbqvwpF3/aycXGuqt3d5GzkviMggffZ2s 70bsvIFMByiE4obsTSr2bsnk5BFO+qnva9Ry+yb2ToAkbJMdXOzIOn6rgbENpoQ9 y/sem5fjOZZgAQTfmGvbp/lL3J4mr2Wg80t3/xMepUAktPSnWnF//519EFZF5VUa sbJJsO/EGFY6IKalSIGJ =UPAP -----END PGP SIGNATURE----- --Apple-Mail=_396942DE-7251-42FE-AE9C-DA4B2AF1E5EF--