From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=209.132.183.28; helo=mx1.redhat.com; envelope-from=kraxel@redhat.com; receiver=edk2-devel@lists.01.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 738AD2035522A for ; Wed, 8 Nov 2017 01:03:14 -0800 (PST) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 77F2B81DFB; Wed, 8 Nov 2017 09:07:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 77F2B81DFB Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=kraxel@redhat.com Received: from sirius.home.kraxel.org (ovpn-116-41.ams2.redhat.com [10.36.116.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id 380065D6A9; Wed, 8 Nov 2017 09:07:14 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 75B6517532; Wed, 8 Nov 2017 10:07:13 +0100 (CET) Date: Wed, 8 Nov 2017 10:07:13 +0100 From: Gerd Hoffmann To: Heyi Guo Cc: "Ni, Ruiyu" , "Zeng, Star" , "edk2-devel@lists.01.org" , "Dong, Eric" Message-ID: <20171108090713.5hof77t5l3gikpwk@sirius.home.kraxel.org> References: <1958e840-f0fe-6d8e-44d1-03ff9c9dde7b@linaro.org> <0C09AFA07DD0434D9E2A0C6AEB0483103B9B3162@shsmsx102.ccr.corp.intel.com> <734D49CCEBEEF84792F5B80ED585239D5BAB6CB0@SHSMSX104.ccr.corp.intel.com> <734D49CCEBEEF84792F5B80ED585239D5BAB6F41@SHSMSX104.ccr.corp.intel.com> MIME-Version: 1.0 In-Reply-To: User-Agent: NeoMutt/20171027 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Wed, 08 Nov 2017 09:07:14 +0000 (UTC) Subject: Re: [MdeModulePkg/TerminalDxe] Why do we delay 2s for ESC being pressed? X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Nov 2017 09:03:15 -0000 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit On Wed, Nov 08, 2017 at 04:44:37PM +0800, Heyi Guo wrote: > > > 在 11/8/2017 4:34 PM, Ni, Ruiyu 写道: > > No. > > Even a terminal tool can recognize F10, it still needs to translate it into "ESC [ V" > > and send the three bytes to firmware. > Got it. But the 2 seconds timeout is not for this situation, right? If > terminal tool could translate and send the key sequence, I think it can > complete 3 bytes transfer in a very short time, isn't it? E.g. 9600 baud / 8 > = 1200 Bytes/s (ignore control bits). > > So 2 seconds timeout is still for user to enter the sequence "ESC [ V" > manually? No. Alot of software has this kind of delay because it is recommended in some classic unix documentation to avoid mis-interpreting incomplete terminal control sequences coming from slow terminals. Where a "slow terminal" which actually would need such a long delay is a physical terminal from the 70ies of the last century, or a virtual terminal hooked up over a *really* slow network connection. Reducing the delay from 2 seconds to roughly 0.2 seconds should be pretty safe, things are not that slow any more these days :) HTH, Gerd