From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758079Ab0EXRWj (ORCPT ); Mon, 24 May 2010 13:22:39 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:53051 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758044Ab0EXRWh (ORCPT ); Mon, 24 May 2010 13:22:37 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:subject:date:user-agent:cc:references:in-reply-to :mime-version:content-type:content-transfer-encoding:message-id; b=kl1hkKOD4MC6G3ZLeJmtKebOfdtcyXY9ahzZyTlF6bbldtb+X2K+/SmKxxglDQJM77 ZhCqBQxluSPbqVaYFXG4OtQbUp/amz88MjSWop7ckEdeYxWrEFyEk6cnGbHctnJ4pPa6 NlRNr7uo54TL6raM/Rj3100Scl9mZgMxm8Mjg= From: Dmitry Torokhov To: Ping Cheng Subject: Re: [PATCH 2/2] input: mt: Document the MT event slot protocol (rev2) Date: Mon, 24 May 2010 10:21:02 -0700 User-Agent: KMail/1.13.2 (Linux/2.6.32.12-115.fc12.x86_64; KDE/4.4.2; x86_64; ; ) Cc: Peter Hutterer , Henrik Rydberg , Andrew Morton , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Mika Kuoppala , Benjamin Tissoires , Stephane Chatty , Rafi Rubin , Michael Poole References: <1274213429-22667-1-git-send-email-rydberg@euromail.se> <20100524155901.GB3182@core.coreip.homeip.net> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201005241021.02731.dmitry.torokhov@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 24 May 2010 10:06:15 am Ping Cheng wrote: > On Mon, May 24, 2010 at 8:59 AM, Dmitry Torokhov > > wrote: > > On Sun, May 23, 2010 at 11:07:27PM -0700, Ping Cheng wrote: > >> On Sun, May 23, 2010 at 9:58 PM, Peter Hutterer > >> > >> wrote: > >> >> > And yes, you could add it once we find it's an issue, but by then > >> >> > someone has already spent time to work around this. And when you > >> >> > then start sending slot events all the time, you admit that > >> >> > writing the workaround was just a time waster :) > >> >> > >> >> Work around what, exactly? > >> > > >> > I was referring to having a protocol where processes has to ignore > >> > contacts already down until they've been there when a contact was > >> > pressed (and your comment that if this becomes an issue it could be > >> > added lateron). Now, the ignoring part needs to be written (this is > >> > the "workaround" referred to above). if you're planning to add it > >> > later, we need to cater for that part as well then, having two > >> > implementations depending on the kernel versions. > >> > > >> > but this is just for clarification, it's a moot point anyway given > >> > that button events have the same behaviour. > >> > >> This topic is outside of the _MT_ protocol discussion. > >> > >> However, it is indeed an issue with all filtered input events, both > >> for MT and regular ones. > >> > >> I think we need to add an ioctl to enable user land driver/client to > >> signal the kernel driver to send all events without filtering, just > >> once. Hot-plugged devices and X driver starts after user has contacted > >> with the device are two examples that the client would miss filtered > >> events. > >> > >> Dmitry, do you think it is a valid suggestion? > > > > What about using EVIOCGKEY/EVIOCGSW/EVIOCGABS? > > Those EVIOCs only give us the static values (max/min/supported keys, > etc.). We need their dynamic input data here, the actual x, y, > button, pressure, etc. Am I missing something about those EVIOs? > Yes you are ;) Supported events are reported via EVIOCGBIT, EVIOCGKEY and EVIOCGSW will return current state of keys/switches. As far as EVIOCGABS goes, it also returns, besides min/max/etc, last reported _values_ of the ABS_* events. -- Dmitry