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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 8DDE2C433B4 for ; Fri, 30 Apr 2021 22:50:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6EE1F6135B for ; Fri, 30 Apr 2021 22:50:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232317AbhD3Wut (ORCPT ); Fri, 30 Apr 2021 18:50:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232306AbhD3Wus (ORCPT ); Fri, 30 Apr 2021 18:50:48 -0400 Received: from mail-io1-xd29.google.com (mail-io1-xd29.google.com [IPv6:2607:f8b0:4864:20::d29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B0FF2C06138B for ; Fri, 30 Apr 2021 15:49:59 -0700 (PDT) Received: by mail-io1-xd29.google.com with SMTP id k25so26189112iob.6 for ; Fri, 30 Apr 2021 15:49:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fatalsyntax-com.20150623.gappssmtp.com; s=20150623; h=mime-version:content-transfer-encoding:cc:subject:from:to:date :message-id:in-reply-to; bh=2wqJHexqn8jcOOVd9wSat+g8MvAeP2fqTz/IY+99qj0=; b=KgPumcEuTrAXvBWlAFi43w0rjTeiVvUQf3cYemzccxZWhLifQXI/LmHA0TQY9098lu 6/d84mb/wMGi3K0stSDzxD0KdR9a3JnnABlvgfK9WVYa3oFV2g/EmKUalCDcrffLX03W VMVIXUdgnyVavSZUAqCGDkyLkR/BC0iztLrW/NRReBWSuKVVeMEvyzNBmYJF5fyvcoHA 5jxK1bF4V725RWPcOfiSvjn/fxdp/ge6Q3GXbmI1bpKztKqhAliCOLJepjoXB8mcFeg6 STSlUiOuzQJNYTcj4FBFoaNhr4ij2zEi5MSRX1aWjeiwDxLAfkHsmWv6y/0BObWLUlJi 2Eww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:content-transfer-encoding:cc :subject:from:to:date:message-id:in-reply-to; bh=2wqJHexqn8jcOOVd9wSat+g8MvAeP2fqTz/IY+99qj0=; b=Ktd11Y+4+6TxO1sTbXfFemHwLsqG3euGBFf61IvBw1ix1z618/u1HWHd/0CNom31EJ oEFNxCv+Ydy+5v3i0RF08NkOBIXYlZFchoh8WsxbywFhyrtc/GQe5wNyq6JobvIZ5Ikt 6mAvR8Icw9EEqIkCcCO7R2CcUSC6AcwtlFBu4wkikj6OquToYR3K2QWfybkOf+Yp7kX5 /EVNA/MUgYY2GGRBbYEIGb59dqobgMXuT2G7zArO8ObqSnPR2XZoVwm98IgrN+C9uz4o dNYFepzYN6YZAVDbkPQXM7KbMl73RRFCwh6JXvjie3a6GoNNa0sBKf5mDRBwGvAh6gHg mZGA== X-Gm-Message-State: AOAM530yZjWJE8DfVs6zdOFWw5IXa5dRuBEcXfBspCB1WcxQnaOL3C8H AOhJm7J1nJ+B6aD8g3DTVafbUQ== X-Google-Smtp-Source: ABdhPJwAggpk9lNg7ha/NBDPxA2bMISeFgXGI7HOGYv8+px+pc26fUIsrRaqZhii//jbFeTkIGghOQ== X-Received: by 2002:a05:6602:15d4:: with SMTP id f20mr5572440iow.201.1619822999102; Fri, 30 Apr 2021 15:49:59 -0700 (PDT) Received: from localhost (2603-6000-ca08-f320-6401-a7ff-fe72-256d.res6.spectrum.com. [2603:6000:ca08:f320:6401:a7ff:fe72:256d]) by smtp.gmail.com with ESMTPSA id p5sm224554ilm.63.2021.04.30.15.49.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 30 Apr 2021 15:49:58 -0700 (PDT) Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Cc: , , , "Alex Williamson" Subject: Re: [PATCH] pci: add NVMe FLR quirk to the SM951 SSD From: "Robert Straw" To: "Bjorn Helgaas" Date: Fri, 30 Apr 2021 17:34:24 -0500 Message-Id: In-Reply-To: <20210430205105.GA683965@bjorn-Precision-5520> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri Apr 30, 2021 at 3:51 PM CDT, Bjorn Helgaas wrote: > Please make your subject line match ffb0863426eb ("PCI: Disable > Samsung SM961/PM961 NVMe before FLR") Understood, I will send a revision ASAP. > There's always the possibility that we are doing something wrong in > Linux *after* the FLR, e.g., not waiting long enough, not > reinitializing something correctly, etc. In my experience I was not able to get my particular drive to enter this state while issuing various types of resets purely from the Linux host.=20 The issue only appeared when I pass the device to a KVM guest *and allow that guest to cleanly shut-down.* The last part is crucial: if the guest=20 is forcibly powered off Linux was able to reset the drive just fine. So I suspect the issue here is related to the interaction between whatever state the guest leaves the NVMe drive in, and the Linux kernel's= =20 own reset code triggering some pathological behavior in the controller. FWIW even a remove/rescan, with an interim suspend to RAM, was not enough to unfreeze the controller. The only way I've found to get the device back (apart from this patch) was a full reboot.