From patchwork Mon Nov 13 18:56:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jim Quinlan X-Patchwork-Id: 743543 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A47CD1DA4D for ; Mon, 13 Nov 2023 18:56:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="NgRlkj2/" Received: from mail-oi1-x229.google.com (mail-oi1-x229.google.com [IPv6:2607:f8b0:4864:20::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA1721702 for ; Mon, 13 Nov 2023 10:56:13 -0800 (PST) Received: by mail-oi1-x229.google.com with SMTP id 5614622812f47-3b6f4d8ddccso334289b6e.0 for ; Mon, 13 Nov 2023 10:56:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; t=1699901773; x=1700506573; darn=vger.kernel.org; h=message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=LBtmRDdM2QwWZgow554SZJ2Idr42Xl1EIctNZ5wkrIg=; b=NgRlkj2/e+m7FtEZ6kpRjfbZXKfTiTZrePEL2GF0zdiA0de326RkAdanvp0glsLRNT jVaE6WVedtfsnMj4FJ7Stc3QlZbcWN7UdY3FIvg5vwRjis36a6l+v0/4g0fRdv71a+dP fEgd0tgAD4De8Jb37gAMMqQmLDZB3Qd25c90U= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699901773; x=1700506573; h=message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=LBtmRDdM2QwWZgow554SZJ2Idr42Xl1EIctNZ5wkrIg=; b=wC0nYdFYocKRei8PFAgJlwm5LNLljKWZ4RXCQ9+ihc28eeJO9L4GuOgJrxjfm9r77D ZvApkxa4NHD1EL1/xa8qUUcwK4FEnoV3nF/mYEFHcqkqmNRx1ijHEqPsRGDbStlWlPCn 4k/DVmRhwLUyl1xVmEP/4ba9KfM33GFNAyZ4/MuZt/+hq5Pb+6cmIXWwp1wMLOXPNqQ3 +U7eESkVIxXfx12ijllGRrMq1U9phtpca8IaxyZvLuJQ5MlOMwNeeewaEDrIxxK/XBFg FhQTwkqhEDN2vcCUWPWKMvjjz5MoGKAtrs/fSQ43Ltsz6Sv6heiSbYB730U0Qp3usrBU 5Sjg== X-Gm-Message-State: AOJu0Yx0xhN/rJpJjJrT9bRDyI1UZam1vy3apa0CQCJKBLExgZifNf6Y ehmjsKGZ9cm4S+infLizkHj1FQ== X-Google-Smtp-Source: AGHT+IFS5SasBmECJ/tk7P+h1ZRJrAbM3+XK567jgpWI5zJCovVrs3bsSyr2+G3mVh0uP3aB3TaoHQ== X-Received: by 2002:a05:6808:1413:b0:3b2:dc66:1673 with SMTP id w19-20020a056808141300b003b2dc661673mr9286135oiv.9.1699901773160; Mon, 13 Nov 2023 10:56:13 -0800 (PST) Received: from stbsrv-and-01.and.broadcom.net ([192.19.144.250]) by smtp.gmail.com with ESMTPSA id b187-20020a6334c4000000b0056b27af8715sm4366421pga.43.2023.11.13.10.56.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Nov 2023 10:56:12 -0800 (PST) From: Jim Quinlan To: 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: Conor Dooley , devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS), Florian Fainelli , Jim Quinlan , Krzysztof Kozlowski , =?utf-8?q?Krzyszto?= =?utf-8?q?f_Wilczy=C5=84ski?= , linux-arm-kernel@lists.infradead.org (moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE), linux-kernel@vger.kernel.org (open list), linux-rpi-kernel@lists.infradead.org (moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE), Lorenzo Pieralisi , Rob Herring Subject: [PATCH v8 0/2] PCI: brcmstb: Configure appropriate HW CLKREQ# mode Date: Mon, 13 Nov 2023 13:56:04 -0500 Message-Id: <20231113185607.1756-1-james.quinlan@broadcom.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: V8 -- Un-advertise L1SS capability when in "no-l1ss" mode (Bjorn) -- Squashed last two commits of v7 (Bjorn) -- Fix DT binding description text wrapping (Bjorn) -- Fix incorrect Spec reference (Bjorn) s/PCIe Spec/PCIe Express Mini CEM 2.1 specification/ -- Text substitutions (Bjorn) s/WRT/With respect to/ s/Tclron/T_CLRon/ v7 -- Manivannan Sadhasivam suggested (a) making the property look like a network phy-mode and (b) keeping the code simple (not counting clkreq signal appearances, un-advertising capabilites, etc). This is what I have done. The property is now "brcm,clkreq-mode" and the values may be one of "safe", "default", and "no-l1ss". The default setting is to employ the most capable power savings mode. 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 (2): dt-bindings: PCI: brcmstb: Add property "brcm,clkreq-mode" PCI: brcmstb: Configure HW CLKREQ# mode appropriate for downstream device .../bindings/pci/brcm,stb-pcie.yaml | 18 ++++ drivers/pci/controller/pcie-brcmstb.c | 96 +++++++++++++++++-- 2 files changed, 104 insertions(+), 10 deletions(-) base-commit: 305230142ae0637213bf6e04f6d9f10bbcb74af8 Reviewed-by: Rob Herring