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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F370FC433F5 for ; Wed, 5 Oct 2022 23:55:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229694AbiJEXzH (ORCPT ); Wed, 5 Oct 2022 19:55:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229608AbiJEXzE (ORCPT ); Wed, 5 Oct 2022 19:55:04 -0400 Received: from mail-qt1-x830.google.com (mail-qt1-x830.google.com [IPv6:2607:f8b0:4864:20::830]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4DE50474F8 for ; Wed, 5 Oct 2022 16:55:03 -0700 (PDT) Received: by mail-qt1-x830.google.com with SMTP id cj27so163186qtb.7 for ; Wed, 05 Oct 2022 16:55:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:reply-to :message-id:subject:cc:to:from:date:sender:from:to:cc:subject:date :message-id:reply-to; bh=0XThhC9U9uKIxJQZ665eKAgfnugmApozs76ScmLZwBk=; b=KSYASXbbQEnw9dIt1qkDOuDA0+QasmExuyaVSAsBd91F6GmYOyH0wPFBbWUd2SDuPt Kd3u4wpivOfmtt4sWJlNrFFkqqvV8f0DLJWsedYyEQOqFKG+4wYoNjmU7UYmwonJVgba UcykNav6fHuYOn2yHnk2YZrMx+dCZo4vkbYcBCbl5DKSGnKd0K3+enoOoQAZ5rYJdP8F Eialm1q0BgCKh4h3pSS8fGqJqacuW9K5WknGiJPDgtOre9+AO9L9f09d5iCjyJTo5rlg xCxAG2+koKTtIHDpzRUMp5XtfSIe8foYuVUlkWUe0f/R5mxhDmn31CETqJUaSCXCWqAX 7OWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:reply-to :message-id:subject:cc:to:from:date:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=0XThhC9U9uKIxJQZ665eKAgfnugmApozs76ScmLZwBk=; b=Ab+FSP0HaeiqJfe59gpiqQYvBG8Uj5OTBLWeUOxhj5psmMT0vHBSb4PI8J6roe13AQ jTP2+bPMDqv6NkLU3GwSja/AWywsQijWG5/SvH6NSUycGlcZ5ohLp8o1vqoessya2q56 YJasZoWWV399Sy2dP5Yg4UG9LOCeT8eDjxrGZLo/X/oY/Jxg93iDD6PY4wfUE4WrFYYl 9lelmESdJzyRARdpVQ2LxM+Apaz12qr3EboC/ftQh1LJ8MqYLZDqEdiggwr3Lo5o3hhY OJwsJj71Q1qA6xBs1HtpCUWAKtGRofDqdsPMsmBumVGZu+9J7XUmoSOaoWAVwx8HUlwQ o6bw== X-Gm-Message-State: ACrzQf1RHM37Eiu+GNqhI7/cLZRgRo8L0HLI5tbGRULFAGWSqzzP+CMu jNP6p1dm0/861lynFJf9BQ== X-Google-Smtp-Source: AMsMyM4eROnmK5/Ehiq7Es0N/CNTVAElIT81oT1dQCstYathZwqVIbJlW0dOv1IpRAIF68hTPKC4ZA== X-Received: by 2002:ac8:7d13:0:b0:35c:e54e:9c8 with SMTP id g19-20020ac87d13000000b0035ce54e09c8mr1590034qtb.320.1665014102301; Wed, 05 Oct 2022 16:55:02 -0700 (PDT) Received: from serve.minyard.net ([47.184.185.126]) by smtp.gmail.com with ESMTPSA id bi27-20020a05620a319b00b006ce611aef61sm19661018qkb.95.2022.10.05.16.55.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Oct 2022 16:55:02 -0700 (PDT) Sender: Corey Minyard Received: from minyard.net (unknown [IPv6:2001:470:b8f6:1b:2d13:71e3:7ea0:219]) by serve.minyard.net (Postfix) with ESMTPSA id 22E3F180015; Wed, 5 Oct 2022 23:55:01 +0000 (UTC) Date: Wed, 5 Oct 2022 18:54:59 -0500 From: Corey Minyard To: Andrew Jeffery Cc: openipmi-developer@lists.sourceforge.net, linux-aspeed@lists.ozlabs.org, openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] ipmi: kcs: Poll OBF briefly to reduce OBE latency Message-ID: Reply-To: minyard@acm.org References: <20220812144741.240315-1-andrew@aj.id.au> <08c20621-e75d-4a72-82e6-b1980304e20a@app.fastmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <08c20621-e75d-4a72-82e6-b1980304e20a@app.fastmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 06, 2022 at 09:42:57AM +1030, Andrew Jeffery wrote: > Hi Corey, > > On Sat, 13 Aug 2022, at 00:17, Andrew Jeffery wrote: > > The ASPEED KCS devices don't provide a BMC-side interrupt for the host > > reading the output data register (ODR). The act of the host reading ODR > > clears the output buffer full (OBF) flag in the status register (STR), > > informing the BMC it can transmit a subsequent byte. > > > > On the BMC side the KCS client must enable the OBE event *and* perform a > > subsequent read of STR anyway to avoid races - the polling provides a > > window for the host to read ODR if data was freshly written while > > minimising BMC-side latency. > > Just wondering whether you're happy to pick this one up? I haven't seen > it hit the IPMI tree yet. Sorry. It's in my tree for 6.2 right now. I can't push it up to for-next until 6.1-rc1 comes out. -corey > > Cheers, > > Andrew