Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751655Ab3FYVaq (ORCPT ); Tue, 25 Jun 2013 17:30:46 -0400 Received: from pyr75-3-78-192-68-46.fbxo.proxad.net ([78.192.68.46]:41774 "EHLO molly.corsac.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751102Ab3FYVap (ORCPT ); Tue, 25 Jun 2013 17:30:45 -0400 Message-ID: <1372195837.8189.42.camel@scapa> Subject: Re: [PATCH 0/3] Fix backlight issues on some Windows 8 systems From: Yves-Alexis Perez To: Matthew Garrett Cc: linux-acpi@vger.kernel.org, seth.forshee@canonical.com, joeyli.kernel@gmail.com, daniel.vetter@ffwll.ch, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, lenb@kernel.org, rjw@sisk.pl, Henrique de Moraes Holschuh Date: Tue, 25 Jun 2013 23:30:37 +0200 In-Reply-To: <20130625211415.GA2899@srcf.ucam.org> References: <1370818899-8595-1-git-send-email-matthew.garrett@nebula.com> <1371937599.17761.19.camel@scapa> <20130625160848.GA27123@srcf.ucam.org> <1372193037.8189.24.camel@scapa> <20130625205430.GA2438@srcf.ucam.org> <1372194611.8189.31.camel@scapa> <20130625211415.GA2899@srcf.ucam.org> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-iYRDbqWaQgPY60HgG8kx" X-Mailer: Evolution 3.8.2-1 Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2691 Lines: 65 --=-iYRDbqWaQgPY60HgG8kx Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On mar., 2013-06-25 at 22:14 +0100, Matthew Garrett wrote: > On Tue, Jun 25, 2013 at 11:10:11PM +0200, Yves-Alexis Perez wrote: > > On mar., 2013-06-25 at 21:54 +0100, Matthew Garrett wrote: > > > I agree, we should standardise the behaviour. And the only way we can= =20 > > > standardise the behaviour is to leave it up to userspace. > > >=20 > > It's pretty clear we disagree on this and that my opinion won't really > > matter here. But letting userspace handle that just means broken > > functionality for those who have the chance (apparently) to have an ACP= I > > backlight interface. >=20 > Which, as we've already established, you don't - Lenovo broke it. Your= =20 > Thinkpad claims to have 100 available levels, and most of them don't=20 > work. The kernel has no way of knowing which levels work and which=20 > don't, so leaving this up to the kernel won't actually fix your system= =20 > either. I was referring to =E2=80=9Cstandardize the behaviour by leaving up to userspace=E2=80=9D. A lot of thinkpads (for example) (all the pre-windows 8 ones) have a perfectly working ACPI backlight interface. Also, if the kernel has no way of knowing which levels work, I fail to see how userspace can do better. I understand that switching to intel_backlight instead of acpi_video0 follows what Windows 8 recommends but for me it looks orthogonal to the fact ACPI methods now have some awkward (Lenovo) or broken (Dell). I mean, it's not the first time firmware people break some kernel behavior. I know it's usually not easy to contact them, but shouldn't those methods be fixed, instead of somehow blindly switching to graphic drivers? --=20 Yves-Alexis --=-iYRDbqWaQgPY60HgG8kx Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.20 (GNU/Linux) iQEcBAABCAAGBQJRygv9AAoJEG3bU/KmdcClmbkH/3YF65kIl72TTk+5m3EbkYMP ICKVC4ag5Sb0J/GVzSjo5o2TdDUG3pJUNCeqpsA7z9ummsApzHBuxSNh+IAwF0bK /2rTagXSB1zM7/TiQDNNg/vA3jZuJQYNS/CKYAQ34CLtigJwU6XDehUU0+DWkglS 2dMAGimCl/OrmCtL2y3C2c+cNdQL4EtdBKU8iA5OGKiUVcJ0uS8FzTdE+UNbh7O7 7V39weyumzFveZHq70hrIzOK/bO+6bOk0qW4oCBhlmAw76l/ZyymaBtxaTVw7i2M 4BHSqCtHsz8WTc5bE/PTPVhkJWXc4+g66LL8W5++RLPpxF01mS04knMconaRAuI= =8vBi -----END PGP SIGNATURE----- --=-iYRDbqWaQgPY60HgG8kx-- -- 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/