From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [linux-pm] [RFC] input: syfs switches for SKE keypad Date: Wed, 13 Oct 2010 21:20:59 +0200 Message-ID: <20101013192059.GA24465@elf.ucw.cz> References: <33A307AF30D7BF4F811B1568FE7A9B180460D32FE2@EXDCVYMBSTM006.EQ1STM.local> <20101005174106.GA21399@core.coreip.homeip.net> <4CAC340B.90207@codeaurora.org> <33A307AF30D7BF4F811B1568FE7A9B180461062FE6@EXDCVYMBSTM006.EQ1STM.local> <1286358518.26914.23.camel@4fid08082> <20101013071106.GC1610@ucw.cz> <87tykqc7wq.fsf@tac.ki.iif.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <87tykqc7wq.fsf@tac.ki.iif.hu> Sender: linux-input-owner@vger.kernel.org To: Ferenc Wagner Cc: Onkalo Samu , ext Sundar R IYER , Linus WALLEIJ , Naveen Kumar GADDIPATI , Dmitry Torokhov , "linux-pm@lists.osdl.org" , "linux-input@vger.kernel.org" , Jayeeta BANDYOPADHYAY List-Id: linux-pm@vger.kernel.org Hi! On Wed 2010-10-13 19:35:49, Ferenc Wagner wrote: > Pavel Machek writes: > > >> For mobile devices it is not acceptable to filter events away at some > >> upper SW layer depending on the system state. The HW which generates > >> those events may not generate events at all to allow longer CPU sleep > >> periods. Actually, I question this, too. Obviously, touchscreen needs to be turned off, but how common are accidental button presses? > >> In ideal world it would be nice to control device states based on for > >> example user count. However, there are several listeners for input > >> devices and it is hard or impossible to have them all to follow overall > >> state transition (screen blanked etc.). Instead, there is some > >> system > > > > So you have mobile device; why is it impossible to just close the > > device when you do not want the events? I guess it is hard for generic > > distros, but on your phone, you should be able to modify Xserver to > > close touchscreen/keypad device when it is not needed... right? > > We'd had this discussion before... cf. eg. > http://thread.gmane.org/gmane.linux.kernel.input/9266/focus=9767 > > The problem was that several processes may have a device open, while > another process should be able to control the state of the device. > Maybe this could be solved by making the controlling process a proxy, > and having all "user" processes going though it. Then the Yes, and the proxy is normally called "X server". We already have it. > (proxy) process could open/close the device as it wants, letting the > runtime PM do its job. But this would mean duplicating some kernel > functionality (at least multiplexing) in user space. Yes. We already do that. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html