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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 61134C433F5 for ; Wed, 9 Feb 2022 07:49:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id: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-Owner; bh=x5j/j6JHqBhV0YBpBhQsmkWvXY2j88KFvqwyTe/YRz8=; b=HNfed2e6sEDMhAUsnYDbeo6dvI Khhp3a78ZrmbpJYRXCaygDJsVFfTQLktPu4Zb+vuesCVqPt+dmXZY1Myeor+m5g5iTKFbpJle2d/O YTwAsoM0E9xHH7Yh7ocoSkSLLQKNBMjHnXLtQTWzSNTk7IVwg/0tvHkZ/2BwvarxlNUXJmYDjyJ9n RuH3r1b5wyJ3VZyRogiI1c3JuHryj79evvn0GRam+NDhGa6pdWSoHt2PfXtGhzPqRzMgxmBNz18GF XDc4asuLfnhA5tW3RXlrOGCmZP/OZjcunMkSUdFb5z2d2rf1ZSqUy+Hk4bEwBXde6lz1N7owglOtS wuWNx/BA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHhig-00GWlh-KJ; Wed, 09 Feb 2022 07:48:54 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHhid-00GWlN-Bt for linux-nvme@lists.infradead.org; Wed, 09 Feb 2022 07:48:52 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 1C71668AFE; Wed, 9 Feb 2022 08:48:46 +0100 (CET) Date: Wed, 9 Feb 2022 08:48:45 +0100 From: Christoph Hellwig To: Keith Busch Cc: Christoph Hellwig , linux-nvme@lists.infradead.org, sagi@grimberg.me, Rafael Wysocki , Vidya Sagar Subject: Re: [PATCH] nvme/pci: default to simple suspend Message-ID: <20220209074845.GA9540@lst.de> References: <20220201165006.3074615-1-kbusch@kernel.org> <20220202075502.GA18474@lst.de> <20220202160334.GB3077632@dhcp-10-100-145-180.wdc.com> <20220204071012.GA28638@lst.de> <20220207160655.GB635727@dhcp-10-100-145-180.wdc.com> <20220208143751.GA25260@lst.de> <20220208171421.GA1168214@dhcp-10-100-145-180.wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220208171421.GA1168214@dhcp-10-100-145-180.wdc.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220208_234851_601748_C50268A3 X-CRM114-Status: GOOD ( 15.57 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Feb 08, 2022 at 09:14:21AM -0800, Keith Busch wrote: > > I don't think this will work, as most older platforms just won't have > > that attribute at all, and non-ACPI platforms most certainly won't have > > it. We'll need more quirks in the core PCI/PM code like we did for the > > AMD mobile platforms. > > old platform + old kernel -> simple suspend > > old platform + new kernel -> nvme pm > > This inevitably introduced regressions. Why should we need to quirk old > platforms for a feature that didn't even exist when they were made? > Shouldn't the quirk be the other way around? Because they are broken? If we do get a suspend request that does not explicitly asks for the device do be disabled we need to be able to rely on that. Where we is not just nvme, but any driver.