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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDDBAC7618D for ; Thu, 6 Apr 2023 18:53:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240069AbjDFSx0 (ORCPT ); Thu, 6 Apr 2023 14:53:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229806AbjDFSxZ (ORCPT ); Thu, 6 Apr 2023 14:53:25 -0400 Received: from mail-qt1-x836.google.com (mail-qt1-x836.google.com [IPv6:2607:f8b0:4864:20::836]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A59D86A5; Thu, 6 Apr 2023 11:53:24 -0700 (PDT) Received: by mail-qt1-x836.google.com with SMTP id a5so38978609qto.6; Thu, 06 Apr 2023 11:53:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680807203; x=1683399203; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=Fkm1WIFQjf0PCje4i/w8NoBsWJO6GDFcmZxAmQoOl44=; b=Hk/h42787AxVBPwrLukrVXWSP1EEwYZ86x+YO7gowFQsitDPKp4OEua9Zuw8kAd6yD afvTz75pYSlKCpKUWGjbSbU2i+x1Adq/w8CT3r2sz1Om3L3i6/3ie8rB6AjJgizhnhPU HP+tQp9otXm5oXhhrrR7xy+NvquFJ99RNOB9nOQTbwRMm2pE2ckrbkO3KKiKmF03V5hj bnifesflc1ds0hnR8rHGoRhsd8cgrwcGIuE6qJAiJ8ddt+KrPZlOPjrNEpSb7E784PMI e6Fu43GE0QVTOAwq/Yuks2S+Un57LPeEb28vEtp9u15Wa+V7GVUSO9TwoFkeBjExVbQI hV7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680807203; x=1683399203; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Fkm1WIFQjf0PCje4i/w8NoBsWJO6GDFcmZxAmQoOl44=; b=gsfjtdmjn6mAbbc5pKnmIF5hzb56yetM0Iz9eozKlDjVOm8fD3E6b6fZ0sp78HnUY6 daMjnrdVprt+HlYC2RY3NyVqpjdPzpn3B6EmOFuLMwgNvv3yA49G5Egsy9Dfxb6BrFmr r+hi2TP4/GozPc7K57SodvzqYrY0PgOrnoVYLNVRZv+vZErFo96ZJGqxKuPuhTLPKkRZ momuL4tE4cHwJsSs3R5+Qmnv0Rd9YUA3BLCHjSQjvh3/JgJtm0/jgNotuN2WtT9r73f+ Ip+FcAq9HtBW/tJ5htuR6fwk3Se4WviLniBRgT7lgDsFM2Se7tYzHbpM9fHqtKwt0wRi eK9g== X-Gm-Message-State: AAQBX9cClAyA5sZDviUPPh9zjsXhhe9j8K6MK0ZkjU3sVn17zxcwS0Ad FZJQ0YnLfVnDKNMEXkpNDCg= X-Google-Smtp-Source: AKy350Ygh+Zln0AyES3s+WW8OVnCmQVo50LSQ2mA1GXiXZIQpWrUZIfgBe1uOlV3Zzi7dprgaHTmyA== X-Received: by 2002:a05:622a:202:b0:3e3:8bbc:d152 with SMTP id b2-20020a05622a020200b003e38bbcd152mr11802926qtx.66.1680807203095; Thu, 06 Apr 2023 11:53:23 -0700 (PDT) Received: from [10.67.48.245] ([192.19.223.252]) by smtp.googlemail.com with ESMTPSA id w24-20020ac86b18000000b003e64490a35bsm609139qts.21.2023.04.06.11.53.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 06 Apr 2023 11:53:22 -0700 (PDT) Message-ID: <9e98496b-73a0-78a5-e890-7d7e4be1f469@gmail.com> Date: Thu, 6 Apr 2023 11:53:19 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH v1 1/3] dt-bindings: PCI: brcmstb: Add two optional props Content-Language: en-US To: Krzysztof Kozlowski , Jim Quinlan , linux-pci@vger.kernel.org, Nicolas Saenz Julienne , Bjorn Helgaas , Lorenzo Pieralisi , Cyril Brulebois , Phil Elwell , bcm-kernel-feedback-list@broadcom.com, james.quinlan@broadcom.com Cc: Lorenzo Pieralisi , =?UTF-8?Q?Krzysztof_Wilczy=c5=84ski?= , Rob Herring , Krzysztof Kozlowski , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list References: <20230406124625.41325-1-jim2101024@gmail.com> <20230406124625.41325-2-jim2101024@gmail.com> From: Florian Fainelli In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 4/6/23 11:34, Krzysztof Kozlowski wrote: > On 06/04/2023 14:46, Jim Quinlan wrote: >> Regarding "brcm,enable-l1ss": >> >> The Broadcom STB/CM PCIe HW -- which is also used by RPi SOCs -- requires >> the driver probe to configure one of three clkreq# modes: >> >> (a) clkreq# driven by the RC >> (b) clkreq# driven by the EP for ASPM L0s, L1 >> (c) bidirectional clkreq#, as used for L1 Substates (L1SS). >> >> The HW can tell the difference between (a) and (b), but does not know >> when to configure (c). Further, the HW will cause a CPU abort on boot if >> guesses wrong regarding the need for (c). So we introduce the boolean >> "brcm,enable-l1ss" property to indicate that (c) is desired. This >> property is already present in the Raspian version of Linux, but the >> driver implementaion that will follow adds more details and discerns >> between (a) and (b). >> >> Regarding "brcm,completion-timeout-msecs" >> >> Our HW will cause a CPU abort if the L1SS exit time is longer than the >> completion abort timeout. We've been asked to make this configurable, so >> we are introducing "brcm,completion-abort-msecs". >> >> Signed-off-by: Jim Quinlan >> --- >> .../devicetree/bindings/pci/brcm,stb-pcie.yaml | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml >> index 7e15aae7d69e..ef4ccc05b258 100644 >> --- a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml >> +++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml >> @@ -64,6 +64,18 @@ properties: >> >> aspm-no-l0s: true >> >> + brcm,enable-l1ss: >> + description: Indicates that the downstream device is L1SS >> + capable and L1SS is desired, e.g. by setting >> + CONFIG_PCIEASPM_POWER_SUPERSAVE=y. Note that CLKREQ# > > How does CONFIG_PCIEASPM_POWER_SUPERSAVE apply to *BSD? In other words, there should be no OS/Linux specific comments in a Device Tree binding, which would be a friendlier and nicer way of providing the same feedback. -- Florian