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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 89E31C433E1 for ; Thu, 20 Aug 2020 17:12:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A772208B3 for ; Thu, 20 Aug 2020 17:12:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="LliNBby4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730567AbgHTRM4 (ORCPT ); Thu, 20 Aug 2020 13:12:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730448AbgHTRMf (ORCPT ); Thu, 20 Aug 2020 13:12:35 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02AE8C061385 for ; Thu, 20 Aug 2020 10:12:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=sNKOyAN070cUsV8VT5l3bx4jOXj3jbU+B3Xnf+xMJbU=; b=LliNBby4Jz/n3J8MwHRrJ2CQzi o6j9/rormt1Yg0F5ZhXEUvyqbxEHD7jkgg2KjSzf63lvQ3cFu5wq8FRi3WG6kyPEcjoYhzK13hW8y T376qiV0+ZwOI97/wM5AVpa2qUxF0CtK4rHu8JxocQAn0n49vw3o6ULWF+cDs6IHlqINTR0jZib6S ElYPOzdyai+/g6bSIZJKEwjqezLha3dcJrPscd22VAq/UQ+hoeIuAV5FDVDk0v385NeUbh3dVqVXL /nuGd7667wv90lywivb6L3pLCCgWgOYoJJEGlJ4uLJc/zqP0L3IEAQHWSos3Tc7pMIRU0NPEflc2a QMH2hVOg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8o6p-0004aM-1f; Thu, 20 Aug 2020 17:12:15 +0000 Date: Thu, 20 Aug 2020 18:12:14 +0100 From: Christoph Hellwig To: Jens Axboe Cc: "Ahmed S. Darwish" , Keith Busch , linux-nvme@lists.infradead.org, Sagi Grimberg , Chaitanya Kulkarni , linux-kernel@vger.kernel.org Subject: Re: v5.9-rc1 commit reliably breaks pci nvme detection Message-ID: <20200820171214.GA15207@infradead.org> References: <20200817135011.GA2072@lx-t490> <20200817155658.GB1221871@dhcp-10-100-145-180.wdl.wdc.com> <2356f514-9408-6a6f-871d-046984963533@kernel.dk> <20200820170729.GA4116@lx-t490> <83a3d1b6-1eb5-859b-3c5c-287d8d18a99b@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <83a3d1b6-1eb5-859b-3c5c-287d8d18a99b@kernel.dk> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 20, 2020 at 11:10:58AM -0600, Jens Axboe wrote: > To be fair, I've only heard this one complaint about it, so hopefully it's > not too widespread. I'm on an x86-64 laptop myself with nvme, and it works > just fine :-) The cause for this is the weird NVMe of by ones, where 0 in a field means 1. So for the overflow to happen you need a controller that supports USHORT_MAX queue entries. Which don't seem to be all that common.