From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Henrik Rydberg" Subject: Re: [PATCH] Input: evdev - use monotonic clock for event timestamps Date: Fri, 7 Oct 2011 13:05:42 +0200 Message-ID: <20111007110542.GA5333@polaris.bitmath.org> References: <1317624200-9762-1-git-send-email-djkurtz@chromium.org> <20111003090641.GA5615@polaris.bitmath.org> <20111005092341.GB6840@polaris.bitmath.org> <4E8C6B1F.4090904@gmail.com> <20111006034202.GC20217@core.coreip.homeip.net> <20111007063617.GA6167@core.coreip.homeip.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20111007063617.GA6167@core.coreip.homeip.net> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Torokhov Cc: Daniel Kurtz , Chase Douglas , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-input@vger.kernel.org > > if the values don't change. The timestamp axis > > would always change, hence it would always be sent, even if no other > > axes change. Of course, we can mitigate this with special-case > > handling of the ABS_TIMESTAMP in the evdev layer. > > > > I'd prefer if we go this route then: > > 1. Have input core emit this event. Then we could decide if we should > suppress it when suppressing entire packet. If we go this route, we could also make use of the time stamps of the hardware, when existent. > 2. Make it MSC_ event. > 3. Turn it on and off via ioctl since not all users are interested in > this facility. Perhaps it is time for the per-file-descriptor event filters. > OTOH if we do ioctl why don't we simply allow usres select monotnic vs > wall time in event structure. > > Still, why does your clock fluctuate so much that it matters? Yes, some actual experimental timing data would be most interesting. Thanks, Henrik