From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752503AbeCZOpU (ORCPT ); Mon, 26 Mar 2018 10:45:20 -0400 Received: from mail.bootlin.com ([62.4.15.54]:47090 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752154AbeCZOpT (ORCPT ); Mon, 26 Mar 2018 10:45:19 -0400 Date: Mon, 26 Mar 2018 16:45:07 +0200 From: Maxime Ripard To: Chen-Yu Tsai Cc: Joonas =?utf-8?B?S3lsbcOkbMOk?= , dri-devel , Daniel Vetter , David Airlie , linux-kernel , Jernej =?utf-8?Q?=C5=A0krabec?= , linux-sunxi Subject: Re: [linux-sunxi] Preferring cursor plane over overlay plane Message-ID: <20180326144507.s5vit2cb7rjm6csk@flea> References: <5edad360-d05d-1bb8-c1f2-925138784fef@iki.fi> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="blpnstsklbc25qwo" Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180223 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --blpnstsklbc25qwo Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 26, 2018 at 10:22:45PM +0800, Chen-Yu Tsai wrote: > On Mon, Mar 26, 2018 at 10:14 PM, Joonas Kylm=E4l=E4 wrote: > > Hi DRM subsystem developers, > > > > I ran into this patch where overlay plane was switched to cursor plane > > because there was no proper cursor plane available on the display > > hardware: . Can we discuss whether > > to have a policy of using a normal plane for cursor plane in case a > > dedicated HW cursor plane is missing? > > > > Daniel Vetter suggests that it might be fine to use normal plane for > > cursor plane because how to use the plane would be only "a hint to > > userspace" (see the email linked). > > > > My motivation for having this discussion is that the newer Allwinner > > SoCs don't have dedicated HW cursor plane and the sun4i DRM driver > > currently uses the extra planes as overlay planes which makes moving the > > cursor on Xfce4 DE a terrible experience. To have better cursor moving > > experience one overlay plane would need to be sacrificed. >=20 > If you look at the development history, we've never supported cursor plan= es. X can use an overlay to put the cursor though. > At the beginning we supported one main plane and one overlay plane. That = was > it. The Display Engine 1.0 does have support for an extra hardware cursor, > but we haven't done the work to support it yet. I don't know about the > Display Engine 2.0 though. An issue with supporting the hardware cursor we have is that as far as I understood, the cursor plane in DRM has the assumption that it would be an ARGB format. In the first display engine, the format is actually an 8-bit palette with 1 bit of alpha iirc. Maxime --=20 Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com --blpnstsklbc25qwo Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE0VqZU19dR2zEVaqr0rTAlCFNr3QFAlq5B3IACgkQ0rTAlCFN r3SBMA/8DHgdIjUlBzmbc9g0r2iz6DHa6f8cpu46f5jI91r39Nthop6udgpHBq3n INTL4I5SUSw1e9MqPKrDSNE68s8NKgcPW+wn88lJyfz4coQ1jan18/WwCmVu25Rf eFnE3LHOdDvGEjBjVK46N4uZ91zCmFPwE0+wsFrwUWyWrkxMCk3wQYlzTu6Gy3vU wrGL54OpSf9v+sMw68Jk/BBKFCPhtkAdx2qIOPq6tw8Nv7K/MySbnSRJZ3NOLB6d THb2c/QvY/Y1X3ChA7mN0cr2Mze229EiIPcaJoOTWRd6HDES07WRobR6gP6y8a+Y Znk8NKJGTYETphvSd5ubgqGr+zRhzws/t/Ocx6YeLoFFhNkvMflv0eNKDh+94aOK ub6fMfIaJRrDdTWXvaNWQT+n16zYDBtlYuakuVWasQfOr+5fiiU4coDQZ/1NjqGP vWi+uHNWdGVQby5gCSY+2NcXeidiT3Yv8EXul9cj7BZ6f2sSCqxa2q8t64Q6eCp0 ec28tOXrI0vs3NeqeYh5vtuvE6IHk0lAB3+Ydo0jYF81DBl/MBEd+riJ4GSPXDgm +xGunS2Y7Mi+6aSjWTz1GpvWdrFte0YtubmDGGKVnlne8hF0QVp86SxSNrZa25bc vpLA+MTJ7ZnpLdtp6TgvxtD598VqLxsHA9jyKwJcTfms+Q5XAUQ= =za9L -----END PGP SIGNATURE----- --blpnstsklbc25qwo--