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, 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 BA7E7C433C1 for ; Fri, 26 Mar 2021 07:19:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C57C61A4F for ; Fri, 26 Mar 2021 07:19:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230106AbhCZHTY (ORCPT ); Fri, 26 Mar 2021 03:19:24 -0400 Received: from mail-wm1-f52.google.com ([209.85.128.52]:55250 "EHLO mail-wm1-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230130AbhCZHTK (ORCPT ); Fri, 26 Mar 2021 03:19:10 -0400 Received: by mail-wm1-f52.google.com with SMTP id k128so2415523wmk.4; Fri, 26 Mar 2021 00:19:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=fLNL3raZRrGxUJu9e4f1n/rQLMtqVUBuwaA1ykbylUk=; b=p534m1V6PBzMEjxzs3FRwVpNZwDQ6HuSi8PPZ2zbiIsdwTSRNzU5vc/Yayc8yt1Y6A b5YOSkN6W8bVLJ6wcsu49zg7ZQVbCjnJZgXhQlyPesN7i4lzF/yiEgTWgxuq5WqPMb95 tc87t5D8q2F3XDzz1mTUyK+C9OF4VPEZgDgnOCkbNbyhV2hGqDzGHYO6UMpaTBaj0HPX 4dF/apbdmaIM5qTQkZy3LdCmAgLCGFkqAtTShzVLoGhEO+K6+6PRshK6U4uUIFsGx464 WwPLakDhefzPwOQfzpyhr9GboC9x3K4zoz71uUFoGNOgQhFyai6phCv+NHWww+vjucRx BX+w== X-Gm-Message-State: AOAM531LqLoFxZRvm/VfcXCldLmF19t/aD9m0C/n0T0ZojOxofJuzgXe gOG5ROee+rYtalaP8oyPnlk= X-Google-Smtp-Source: ABdhPJzw9FCS1e3r6/gNJEX0b3FR2E4bCH9ja95FbJe61CwUS7gnjiuRlB6fVOR7d9+kCyPWWaxi2A== X-Received: by 2002:a1c:2308:: with SMTP id j8mr11875666wmj.45.1616743148933; Fri, 26 Mar 2021 00:19:08 -0700 (PDT) Received: from rocinante ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id u23sm9760443wmn.26.2021.03.26.00.19.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 26 Mar 2021 00:19:08 -0700 (PDT) Date: Fri, 26 Mar 2021 08:19:07 +0100 From: Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= To: Kishon Vijay Abraham I Cc: Bjorn Helgaas , Rob Herring , Lorenzo Pieralisi , Marc Zyngier , linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Lokesh Vutla Subject: Re: [PATCH 6/6] PCI: keystone: Add workaround for Errata #i2037 (AM65x SR 1.0) Message-ID: References: <20210325090026.8843-1-kishon@ti.com> <20210325090026.8843-7-kishon@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210325090026.8843-7-kishon@ti.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Kishon, A few small nitpicks. > Errata #i2037 in AM65x/DRA80xM Processors Silicon Revision 1.0 > (SPRZ452D–July 2018–Revised December 2019 [1]) mentions when an > inbound PCIe TLP spans more than two internal AXI 128-byte bursts, > the bus may corrupt the packet payload and the corrupt data may > cause associated applications or the processor to hang. > > The workaround for Errata #i2037 is to limit the maximum read > request size and maximum payload size to 128 Bytes. Add workaround > for Errata #i2037 here. The errata and workaround is applicable > only to AM65x SR 1.0 and later versions of the silicon will have > this fixed. I think it would be either "128 B" or "128 bytes", there is no need to capitalise bytes. [...] > + /* > + * Memory transactions fail with PCI controller in AM654 PG1.0 > + * when MRRS is set to more than 128 Bytes. Force the MRRS to > + * 128 Bytes in all downstream devices. > + */ Same here, it would be "128 bytes" in the comment above. [...] > + if (pcie_get_readrq(dev) > 128) { > + dev_info(&dev->dev, "limiting MRRS to 128\n"); > + pcie_set_readrq(dev, 128); > + } [...] Might be nice to add unit here, so "128 bytes". Krzysztof