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 9E305EE49A6 for ; Mon, 21 Aug 2023 14:42:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236091AbjHUOmT (ORCPT ); Mon, 21 Aug 2023 10:42:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236096AbjHUOmR (ORCPT ); Mon, 21 Aug 2023 10:42:17 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13086F0; Mon, 21 Aug 2023 07:42:14 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 655D563A5F; Mon, 21 Aug 2023 14:42:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF976C433C7; Mon, 21 Aug 2023 14:42:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692628932; bh=52OKjdLnV3pWDyoccRcefrV4SrypcfY1Bxxz8eiiXcw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=key8/FoxfX/Cfe3tNBW4IoMMuBqGOTSFlcN9Mplhx1Ln1eR3+jgv+0n+9YvOHaQk1 n60IZ+xZod07cPxz58E21zZ2Ra0rTd5R9Jv926H7aNUI79R6F288GGkTJZxW3WdLVx oGp2hEF8xeCkWcQDWR3JA5Mj4NGGCkNDuwB7bqSJY4tBhpPKMc7BB44Gw5stcqvx4m UuI26qmvFHSPwRixC44a6v15jHrhLf2Ldc5kI9qUQvAuImnRDkh6mBPQC/3VC/fPDT kBgVUmaq78SYChr+hrauXEYzYjgmM3f7lVFBkTbHVYnihVM66UVyruGOWQ2qZNmTi1 NSRvSGFomGvAw== Date: Mon, 21 Aug 2023 16:42:05 +0200 From: Lorenzo Pieralisi To: Jim Quinlan , robh@kernel.org Cc: linux-pci@vger.kernel.org, Nicolas Saenz Julienne , Bjorn Helgaas , Lorenzo Pieralisi , Cyril Brulebois , Phil Elwell , bcm-kernel-feedback-list@broadcom.com, Conor Dooley , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Florian Fainelli , Jim Quinlan , Krzysztof Kozlowski , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , open list , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" Subject: Re: [PATCH v6 0/5] PCI: brcmstb: Configure appropriate HW CLKREQ# mode Message-ID: References: <20230623144100.34196-1-james.quinlan@broadcom.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Mon, Aug 21, 2023 at 08:15:02AM -0400, Jim Quinlan wrote: > On Mon, Aug 21, 2023 at 4:35 AM Lorenzo Pieralisi wrote: > > > > On Fri, Jun 23, 2023 at 10:40:53AM -0400, Jim Quinlan wrote: > > > v6 -- No code has been changed. > > > -- Changed commit subject and comment in "#PERST" commit (Bjorn, Cyril) > > > -- Changed sign-off and author email address for all commits. > > > This was due to a change in Broadcom's upstreaming policy. > > > > > > v5 -- Remove DT property "brcm,completion-timeout-us" from > > > "DT bindings" commit. Although this error may be reported > > > as a completion timeout, its cause was traced to an > > > internal bus timeout which may occur even when there is > > > no PCIe access being processed. We set a timeout of four > > > seconds only if we are operating in "L1SS CLKREQ#" mode. > > > -- Correct CEM 2.0 reference provided by HW engineer, > > > s/3.2.5.2.5/3.2.5.2.2/ (Bjorn) > > > -- Add newline to dev_info() string (Stefan) > > > -- Change variable rval to unsigned (Stefan) > > > -- s/implementaion/implementation/ (Bjorn) > > > -- s/superpowersave/powersupersave/ (Bjorn) > > > -- Slightly modify message on "PERST#" commit. > > > -- Rebase to torvalds master > > > > > > v4 -- New commit that asserts PERST# for 2711/RPi SOCs at PCIe RC > > > driver probe() time. This is done in Raspian Linux and its > > > absence may be the cause of a failing test case. > > > -- New commit that removes stale comment. > > > > > > v3 -- Rewrote commit msgs and comments refering panics if L1SS > > > is enabled/disabled; the code snippet that unadvertises L1SS > > > eliminates the panic scenario. (Bjorn) > > > -- Add reference for "400ns of CLKREQ# assertion" blurb (Bjorn) > > > -- Put binding names in DT commit Subject (Bjorn) > > > -- Add a verb to a commit's subject line (Bjorn) > > > -- s/accomodat(\w+)/accommodat$1/g (Bjorn) > > > -- Rewrote commit msgs and comments refering panics if L1SS > > > is enabled/disabled; the code snippet that unadvertises L1SS > > > eliminates the panic scenario. (Bjorn) > > > > > > v2 -- Changed binding property 'brcm,completion-timeout-msec' to > > > 'brcm,completion-timeout-us'. (StefanW for standard suffix). > > > -- Warn when clamping timeout value, and include clamped > > > region in message. Also add min and max in YAML. (StefanW) > > > -- Qualify description of "brcm,completion-timeout-us" so that > > > it refers to PCIe transactions. (StefanW) > > > -- Remvove mention of Linux specifics in binding description. (StefanW) > > > -- s/clkreq#/CLKREQ#/g (Bjorn) > > > -- Refactor completion-timeout-us code to compare max and min to > > > value given by the property (as opposed to the computed value). > > > > > > v1 -- The current driver assumes the downstream devices can > > > provide CLKREQ# for ASPM. These commits accomodate devices > > > w/ or w/o clkreq# and also handle L1SS-capable devices. > > > > > > -- The Raspian Linux folks have already been using a PCIe RC > > > property "brcm,enable-l1ss". These commits use the same > > > property, in a backward-compatible manner, and the implementaion > > > adds more detail and also automatically identifies devices w/o > > > a clkreq# signal, i.e. most devices plugged into an RPi CM4 > > > IO board. > > > > > > > > > Jim Quinlan (5): > > > dt-bindings: PCI: brcmstb: Add brcm,enable-l1ss property > > > PCI: brcmstb: Configure HW CLKREQ# mode appropriate for downstream > > > device > > > > I am not merging the first two patches since the discussion thread > > is still open and I'd like to understand better what can/should be > > done, sorry. > > Hello Lorenzo, > > This patch-set has been stable for months, V5 was out early May and > the V6 changes > did not involve code. I'm a little surprised that you are voicing > concern at this stage. > > The previous discussions covered all aspects of these commits AFAICT. > Please review > them and the commit messages and let me know what issues you do not understand > or any topics that were not considered. I disagree with the reasoning behind "brcm,enable-l1ss" property usage instead of a command line option - at least I would like to get a comment from DT maintainers about it. I think Bjorn made the point consistently and I also think he is right. I would like to get Rob's opinion on this. I know he acked the DT bindings (I have a comment on those too) but regardless, it is clearly a property used for what is a command line configuration parameter, no two ways about it. Thanks, Lorenzo > > Are you concerned about the Broadcom STB/CM community or the RPi community? > For the former, I have direct communication w/ our customers and none of them > are even close to using upstream (they may backport my commits). For > the latter, I have > tested these commits on the official RPi4 and CM4 IO platforms, and > Cyril has also put in > an admiral amount of testing. > > Note that I have on my desk a CM4 IO board w/ a conventional PCIe > device, and it does not boot > upstream master Linux until these patches are applied. > > Further, Raspian OS has already introduced the "brcm,enable-l1ss" > property but did not upstream it, and > my commits are backwards compatible with this. > > > > > > PCI: brcmstb: Set higher value for internal bus timeout > > > PCI: brcmstb: Assert PERST# on BCM2711 > > > PCI: brcmstb: Remove stale comment > > > > Is it OK to apply these three on their own ? Overall it would be > > great to avoid mixing patches with different end goals in a single > > series. > > Well, they are related for one customer who wants to use L1SS power > savings AND require > a long period for the internal timeout. But, yes, these commits are > fine to apply > independently. > > Regards, > Jim Quinlan > Broadcom STB > > > > > Thanks, > > Lorenzo > > > > > .../bindings/pci/brcm,stb-pcie.yaml | 9 ++ > > > drivers/pci/controller/pcie-brcmstb.c | 91 ++++++++++++++++--- > > > 2 files changed, 89 insertions(+), 11 deletions(-) > > > > > > > > > base-commit: 8a28a0b6f1a1dcbf5a834600a9acfbe2ba51e5eb > > > -- > > > 2.17.1 > > > > > > >