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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 6424AC4707F for ; Thu, 27 May 2021 12:09:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47475613AA for ; Thu, 27 May 2021 12:09:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234928AbhE0MKg (ORCPT ); Thu, 27 May 2021 08:10:36 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:34941 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234976AbhE0MKG (ORCPT ); Thu, 27 May 2021 08:10:06 -0400 Received: from mail-lj1-f200.google.com ([209.85.208.200]) by youngberry.canonical.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lmEoS-0005iH-Dl for linux-kernel@vger.kernel.org; Thu, 27 May 2021 12:08:32 +0000 Received: by mail-lj1-f200.google.com with SMTP id m3-20020a2ea5830000b0290109369442e2so134681ljp.18 for ; Thu, 27 May 2021 05:08:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=kncaMdHs6rlLGylUk3Wdwf3tcaKjfAxUxb/GAcKWx7A=; b=DJOWttWdZVsZMAjbd6OSApndz2GmwBZznOJOtHVyeML1vTGIspYHlQS6MXEMo16EN2 gCF5ZsPDpIbkUEvOLTeZUrsbDVufYgEagc/TeTygnf8/UdVScEz/EMRORCD9nzyw66He sT6J1SaLgDAGgfomjmF7Muvh4Ludk2ybC0gj3LThtOHRYNYHlrBRP5wKUxMFkEKQqpaD oKANpEL6vbKk7d1TRmtug2Wk9ZTkozVvlv5+2Jow8FISZhd5+V8FWkcb4Ul36B4dT81y 0RCJ+NHAkpeVtHaK4EO6uqKtnGO/rCGzvMQpVxM/wkqqlP+pEfc0CJw6YZ5SN5WvWlKs 397Q== X-Gm-Message-State: AOAM530D4TuQc7bibLSlpwhm2SkqFAHemF9AhJRbtcq/vyEL24vKQAh2 PRAkoqhuqhr4hBITvN30gWQC66Hqh5xx0q0Cbu6rAQNQ+zJdhSFeJ3IqwMqV8HJALIYmYHG9W8x LWiVzIOWjLGuQNxVWxSkiWVNbkWOZ+xKEJBEO2L0VCLt8wV0WOGelxKcebw== X-Received: by 2002:a05:651c:3c9:: with SMTP id f9mr2316719ljp.403.1622117311912; Thu, 27 May 2021 05:08:31 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxMy+4w+3mOLCUbgnvd7jc4HyGXspeCGlk4iS6hlGENYk15Z40+kFFkwbWsZI6VxoKOYx3o+IEQ9FOv/BtKb+E= X-Received: by 2002:a05:651c:3c9:: with SMTP id f9mr2316678ljp.403.1622117311449; Thu, 27 May 2021 05:08:31 -0700 (PDT) MIME-Version: 1.0 References: <20210526150633.GA1291513@bjorn-Precision-5520> <20210527114029.GC17266@lst.de> In-Reply-To: <20210527114029.GC17266@lst.de> From: Kai-Heng Feng Date: Thu, 27 May 2021 20:08:19 +0800 Message-ID: Subject: Re: [PATCH] nvme-pci: Avoid to go into d3cold if device can't use npss. To: Christoph Hellwig Cc: Bjorn Helgaas , Keith Busch , Koba Ko , Jens Axboe , Sagi Grimberg , linux-nvme , Linux Kernel Mailing List , Henrik Juul Hansen , Bjorn Helgaas , Linux PCI Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 27, 2021 at 7:40 PM Christoph Hellwig wrote: > > On Thu, May 27, 2021 at 12:24:06AM +0800, Kai-Heng Feng wrote: > > Yes, that's exactly what they said. Because Windows Modern Standby > > always keep the NVMe at D0, so D3hot is untested by the vendors. > > So all the problems we've deal with latetly are that platforms cut the > power off. So it is not kept always at D0 which would be the right thing, > but moved into D3cold. It's still okay to use D3cold under s2idle if nvme_acpi_storage_d3() check passes. Otherwise D0 should be used. I am unsure how to proceed with HMB NVMes if we can't setup DMA after resume... > > Which makes this patch to disable D3cold rather counterintuitive. The intention of this patch is indeed very unclear. Kai-Heng