From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [linux-pm] [PATCH v2 1/2] Input: gpio-keys - allow platform to specify exact irq flags Date: Mon, 7 Dec 2009 20:22:51 -0800 Message-ID: <20091208042251.GB11147@core.coreip.homeip.net> References: <87einfltp3.fsf@tac.ki.iif.hu> <20091206084704.GC2766@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pw0-f42.google.com ([209.85.160.42]:57422 "EHLO mail-pw0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934855AbZLHEWt (ORCPT ); Mon, 7 Dec 2009 23:22:49 -0500 Received: by pwj9 with SMTP id 9so1370107pwj.21 for ; Mon, 07 Dec 2009 20:22:56 -0800 (PST) Content-Disposition: inline In-Reply-To: <20091206084704.GC2766@ucw.cz> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Pavel Machek Cc: Ferenc Wagner , Alan Stern , linux-pm@lists.linux-foundation.org, Mika Westerberg , "linux-input@vger.kernel.org" On Sun, Dec 06, 2009 at 09:47:04AM +0100, Pavel Machek wrote: > Hi! > > > > But runtime-pm.txt says for example: > > > > Generally, remote wake-up should be enabled for all input devices > > put into a low power state at run time. > > > > But in this case the requirement is to suppress input events from a > > given device, effectively muting and putting it into low power state, > > even though it's still open by some other parties. Runtime PM, on the > > other hand tries not to interfere with the normal usage of the device. > > > > Later: > > > > (3) ->runtime_idle() and ->runtime_suspend() can only be executed for a > > device the usage counter of which is equal to zero _and_ [...] > > > > which underlines the difference again: the usage counter (defined by > > common sense) won't be zero in our case, because the device is > > constantly kept open, while we want to mute it, putting it into a low > > power state. > ... > > Actually, this could be implemented by the various users cooperating in > > closing the device, letting it go to sleep automatically. But this > > requires strictly cooperating parties and is more complicated that > > flipping some master switch of the device. We're looking for this > > master switch, before needlessly building our own. > > Please just close the device properly. I do not think we want 100 > different 'please mute keys A and G', 'please mute middle mouse button', > ... interfaces anywhere near mainline. > I do not think it is practical to simply close the device, given that there may be several applications that have it open. I constantly see embedded guys adding custom knobs to the devices allowing them to shut off the device when not in use. Kind of runtame PM but user-initiated. I would really love to have it implemented in the driver core so the interface is the same for all drivers (that support this future). > Or just do it as local patch. I also see that gpio-keys is quite different in the sence that it can shut off buttons selectively. I fact, at the moment every button can be considered a separate device... But that would be too much overhead. They could probably split the keys into 2 groups (critical that should be always active) and not critical, that could be shut off, but I think they want teh flexibility of controlling this at runtime instead of doing it in board data. -- Dmitry