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 2CF66EE645C for ; Fri, 15 Sep 2023 13:43:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235414AbjIONn0 (ORCPT ); Fri, 15 Sep 2023 09:43:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235355AbjIONn0 (ORCPT ); Fri, 15 Sep 2023 09:43:26 -0400 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 10BEA10D; Fri, 15 Sep 2023 06:43:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=MDmOVUGFw7psqGT5ektePsIj1IbCfn8TY/XxeJGVNTw=; b=rtC74pAlfCcyhcB3Wyl8LKCPB0 Xwz14Qd36TL0PKhw7Zk+LHnxUd5XgAmKuJEe7akvV+FC/sROu11SxSxKI+0wEMV+5tyG+iCX3Olrr lO0y6WnYO8QsojbcRYxX9UrQdN/L/OAffvM0kt7yypxuwclbo3I2J8b4RIOb+s/+WUwGejgTGc/Xo dStNDrPrXV6sXo2DJ/ln2JUAiLUi/5f/0lMGJHd3Kav6/MEdvhDb63mrP0ECRMh5DT6Wb67I6BORS s9AtdfQyX3WJB4LjYZCrgQaddENsVW+TeUjrQddQqbbbUdsUALBFXgdcFgNaR305NNyFce8J7knKh AzEeS2ng==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:40636) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qh96C-0005hw-0w; Fri, 15 Sep 2023 14:43:08 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1qh969-0005qV-Do; Fri, 15 Sep 2023 14:43:05 +0100 Date: Fri, 15 Sep 2023 14:43:05 +0100 From: "Russell King (Oracle)" To: Salil Mehta Cc: "Rafael J. Wysocki" , Ard Biesheuvel , Jonathan Cameron , James Morse , "linux-pm@vger.kernel.org" , "loongarch@lists.linux.dev" , "linux-acpi@vger.kernel.org" , "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-riscv@lists.infradead.org" , "kvmarm@lists.linux.dev" , "x86@kernel.org" , Jean-Philippe Brucker , "jianyong.wu@arm.com" , "justin.he@arm.com" Subject: Re: [RFC PATCH v2 27/35] ACPICA: Add new MADT GICC flags fields [code first?] Message-ID: References: <20230913163823.7880-1-james.morse@arm.com> <20230913163823.7880-28-james.morse@arm.com> <20230914155459.00002dba@Huawei.com> <80e36ff513504a0382a1cbce83e42295@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <80e36ff513504a0382a1cbce83e42295@huawei.com> Sender: Russell King (Oracle) Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Fri, Sep 15, 2023 at 09:34:46AM +0000, Salil Mehta wrote: > > > Note that the ACPI spec says enabled + online-capable isn't defined. > > > > > > "The information conveyed by this bit depends on the value of the > > > Enabled bit. If the Enabled bit is set, this bit is reserved and > > > must be zero." > > > > > > So, if x86 is doing something with the enabled && online-capable > > > state (other than ignoring the online-capable) then technically it > > > is doing something that the spec doesn't define > > > > And so it is wrong. > > Or maybe, specification has not been updated yet. code-first? What is the point in speculating. If you want to speculate about it, fine, but please don't use speculation as a reason that "oh we need to sort this out before we can merge the patches". This is precisely why engineers are bad at producing products. They like to continually tweak the design, and the design never gets out the door. You need someone who is a project manager to tell engineers when to stop. Without a project manager to do that, eventually the project fades into insignificance because it becomes no longer relevant or has its funding cut. Hotplug VCPU on aarch64 feels exactly like that - it seems to be an engineer project that is just going to for-ever rumble on and never actually see the light of day. So please - stop speculating and lets get vCPU hotplug *actually* delivered and usable. Even if it's not 100% perfect. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!