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 1B2F9C43214 for ; Mon, 30 Aug 2021 08:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03D1C61008 for ; Mon, 30 Aug 2021 08:36:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234969AbhH3Ihm (ORCPT ); Mon, 30 Aug 2021 04:37:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:51048 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233318AbhH3Ihl (ORCPT ); Mon, 30 Aug 2021 04:37:41 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BDB1460E90; Mon, 30 Aug 2021 08:36:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1630312608; bh=U1Bz+TRPE0qWHJ914Agg77D2LCyxrGJYD98I0IgzduI=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=ACAJ/8opjlZkYWqPkc/po7IKe6UsMR372P2D3M0nWcSwPziCe9rfvwHFNzmGkBF77 AdBnGtgHa3hwiaxGlK/KK6q3dz0IRISJ9AwpWxgij42rEdZ/zS5TEVsPRWC4eHZz6F C5TMhkXbp9q6yLx/NEs0LfsNm/h0K6aGqPmFcM1BTdYDyP0+v1p5a/VCJJw1ngpb21 rp2//0piv30bOzwAhhoXQiOEUpSWjgx1m1jp/VrhZeorH9SOMM/rvVJtoFHSpdFPmx vi0VzTg+CE57l/Ls6Gd8yAlNxNq/HlCPAX8mQLhVdFFIREOqUMDG7AWum71adhq0VU D6NlaGykdHhaw== Message-ID: <44ad79081412af289c68e74cdecb6a2baa2e873c.camel@kernel.org> Subject: Re: [PATCH v3 2/4] PCI: brcmstb: Add ACPI config space quirk From: nicolas saenz julienne To: Jeremy Linton , linux-pci@vger.kernel.org Cc: lorenzo.pieralisi@arm.com, bhelgaas@google.com, rjw@rjwysocki.net, lenb@kernel.org, robh@kernel.org, kw@linux.com, f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Date: Mon, 30 Aug 2021 10:36:43 +0200 In-Reply-To: <20210826071557.29239-3-jeremy.linton@arm.com> References: <20210826071557.29239-1-jeremy.linton@arm.com> <20210826071557.29239-3-jeremy.linton@arm.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.40.4 (3.40.4-1.fc34) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jeremy, sorry for the late reply, I've been on vacation. On Thu, 2021-08-26 at 02:15 -0500, Jeremy Linton wrote: [...] > +static void __iomem *brcm_pcie_map_conf2(struct pci_bus *bus, > + unsigned int devfn, int where) > +{ > + struct pci_config_window *cfg = bus->sysdata; > + void __iomem *base = cfg->win; > + int idx; > + u32 up; > + > + /* Accesses to the RC go right to the RC registers if slot==0 */ > + if (pci_is_root_bus(bus)) > + return PCI_SLOT(devfn) ? NULL : base + where; > + > + /* > + * Assure the link is up before sending requests downstream. This is done > + * to avoid sending transactions to EPs that don't exist. Link flap > + * conditions/etc make this race more probable. The resulting unrecoverable > + * SERRORs will result in the machine crashing. > + */ > + up = readl(base + PCIE_MISC_PCIE_STATUS); > + if (!(up & PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK)) > + return NULL; > + > + if (!(up & PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK)) > + return NULL; Couldn't this be integrated in the original brcm_pcie_map_conf()? IIUC there is nothing ACPI specific about it. It'd also make for less code duplication. Regards, Nicolas