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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 1F15FC47080 for ; Tue, 1 Jun 2021 21:15:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC8AD613C0 for ; Tue, 1 Jun 2021 21:15:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234782AbhFAVRU (ORCPT ); Tue, 1 Jun 2021 17:17:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:52100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234707AbhFAVRS (ORCPT ); Tue, 1 Jun 2021 17:17:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BC3DB613B1; Tue, 1 Jun 2021 21:15:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622582137; bh=MDPBQO0xqyU7JBB9JwRSYLds63k/uuGat5vpQ7A4njc=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=bSuITOEGklerNUdwfdDUPRaa0sv02WeF3vfGVQm+q4QtjNzuW0oQPjWNzhwzFmKdi JGflQXpBM9t+P8cmFT1iXGBnPTImN05mSzaWD9LEHVA+Q1ZvDjjdpeIxrty66S8pCD 8qGJcrx/bhUW3o4Oq1IUH8CVf3O7hABOqojsOw7rJs7dzdNdt4r+aChNgtftDxVQCj bggMptdhhcmXEf7+QXTSYltihHZmBdd6btr6HMKfGnLuMNJdWYWokXGHPyQT76jkTm keQYuYMaBLAGDgi08zIQOJgM4j6zjlxmvewmNiZ91r9YGeyZ5YW6EBXBu58ifEPPGq jp0sq1cGktsXQ== Date: Tue, 1 Jun 2021 16:15:30 -0500 From: Bjorn Helgaas To: Pali =?iso-8859-1?Q?Roh=E1r?= Cc: Marek =?iso-8859-1?Q?Beh=FAn?= , linux-pci@vger.kernel.org, =?iso-8859-1?Q?R=F6tti?= , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= Subject: Re: [PATCH] PCI: Add Max Payload Size quirk for ASMedia ASM1062 SATA controller Message-ID: <20210601211530.GA1972509@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210601170907.GA1949035@bjorn-Precision-5520> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Jun 01, 2021 at 12:09:09PM -0500, Bjorn Helgaas wrote: > On Fri, May 28, 2021 at 02:12:08AM +0200, Pali Rohár wrote: > > On Tuesday 11 May 2021 18:16:12 Marek Behún wrote: > > > Ping? :) > > > > > > Marek > > > > Bjorn: Gentle reminder :) > > The current patch [1] doesn't look mergeable as-is. > > - "ASM1062 SATA controller causes an External Abort on controllers > which support Max Payload Size >= 512" doesn't sound like a > correct description. > > That description suggests the problem is with the *PCI > controller*, not with the ASM1062. I think that's incorrect; I > think the problem is with the ASM1062. > > I would expect something like "ASM1062 advertises Max_Payload_Size > Supported of 512, but in fact it cannot handle TLPs with payload > size of 512." MPS is somewhat complicated, and I don't think we have good documentation in the Linux source. FWIW, this paper has a really good explanation of the MPS (Max Payload Size) and MRRS (Max Read Request Size) concepts: https://www.xilinx.com/support/documentation/white_papers/wp350.pdf