From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9898C433E2 for ; Wed, 16 Sep 2020 18:20:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7583A21655 for ; Wed, 16 Sep 2020 18:20:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727897AbgIPSUN (ORCPT ); Wed, 16 Sep 2020 14:20:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727907AbgIPSUG (ORCPT ); Wed, 16 Sep 2020 14:20:06 -0400 Received: from gofer.mess.org (gofer.mess.org [IPv6:2a02:8011:d000:212::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7481EC061756; Wed, 16 Sep 2020 11:20:00 -0700 (PDT) Received: by gofer.mess.org (Postfix, from userid 1000) id CDB6DC63F3; Wed, 16 Sep 2020 19:19:54 +0100 (BST) Date: Wed, 16 Sep 2020 19:19:54 +0100 From: Sean Young To: Joakim Zhang Cc: "mchehab@kernel.org" , "linux-media@vger.kernel.org" , "linux-kernel@vger.kernel.org" , dl-linux-imx , Andy Duan Subject: Re: [PATCH] media: rc: gpio-ir-recv: add QoS support for cpuidle system Message-ID: <20200916181954.GA27005@gofer.mess.org> References: <20200915150202.24165-1-qiangqing.zhang@nxp.com> <20200915093342.GA24139@gofer.mess.org> <20200915201947.GA4019@gofer.mess.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Joakim, On Wed, Sep 16, 2020 at 10:22:11AM +0000, Joakim Zhang wrote: > > Hi Sean, > > Thanks for your hint, I will send a V2 soon according to your suggestions. > > We also have a concern, since you are a IR expert, may you can give us answers. With this patch, the first frame once press could not been decoded. > AFAIK, IR protocols have not specify how may frames transmitting once press, is there ang criterion to decide this? > > Is it possible that single frame transmitting once pressing? Per my understanding, it will transmit more than one frame. So remotes send IR signals while a button is being pressed down. For the remotes I've seen, when pressing a button a short amount of time will repeat the IR message at least three times. This is a few times when I've tried this, but by no means exhaustive of all remotes or protocols. I think the question you are trying to answer is, if we miss the first message, will we at least have another chance if the message is repeated? So I think the message will be repeated, but the repeat message is not enough for the nec protocol. The nec repeat is a shorter message which does not carry any information apart from "last key still pressed": https://www.sbprojects.net/knowledge/ir/nec.php Thanks, Sean