From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rafi Rubin Subject: Re: [PATCH] dell-wmi Switch support and Tablet switch definition Date: Fri, 19 Jun 2009 16:31:59 -0400 Message-ID: <4A3BF5BF.5030102@seas.upenn.edu> References: <1245410112-13659-1-git-send-email-rafi@seas.upenn.edu> <20090619140228.GA21354@srcf.ucam.org> <4A3BE6F0.7090107@seas.upenn.edu> <20090619194009.GA28382@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from LION.seas.upenn.edu ([158.130.12.194]:56536 "EHLO lion.seas.upenn.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751688AbZFSUcB (ORCPT ); Fri, 19 Jun 2009 16:32:01 -0400 In-Reply-To: <20090619194009.GA28382@srcf.ucam.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Matthew Garrett Cc: linux-acpi@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Matthew Garrett wrote: > On Fri, Jun 19, 2009 at 03:28:48PM -0400, Rafi Rubin wrote: > >> I agree polling the tablet state would be a good thing. But that does not mean we should not >> support the signals until we are ready to support polling. >> >> If you are suggesting that we should not use an EV_SW because we will eventually poll the hardware >> instead of keeping the state in software, then I have no problem with sending keys or other events. > > No, my point is that there's little benefit in providing EV_SW if the > initial value is going to be wrong. Software simply can't depend on it. > The code's absolutely fine, but there's a risk that it'll break > otherwise working desktops until we know how to set the initial value. The signal is not a toggle. Its an explicit "going to tablet" and "coming from tablet". And the initial value is "non-tablet" mode, which is what must be assumed without this support. So the only new case where a wrong assumption may be made is if the screen is flipped out of tablet mode during suspend or hibernate. But we _don't_ have the potential of a toggle being inverted and it rotating the screen to something silly every time you flip it. I think the benefits of the partial support far outweight the potential hazards. That being said, if you have any clue how to probe the state, I would be very happy to help you. And I'd agree that signals can wait. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAko79b8ACgkQwuRiAT9o60+VowCg5zvB16xzUz6w7cqP6twu4xKv 9o0AoJuG3v9qkiB8SXVpk/D9nud2A8FM =h/y8 -----END PGP SIGNATURE-----