From nobody Sun Sep 22 15:37:00 2024 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15281C433FE for ; Thu, 18 Nov 2021 14:09:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2EF361B5F for ; Thu, 18 Nov 2021 14:09:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232634AbhKROMR (ORCPT ); Thu, 18 Nov 2021 09:12:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232673AbhKROMP (ORCPT ); Thu, 18 Nov 2021 09:12:15 -0500 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D949CC061764; Thu, 18 Nov 2021 06:09:15 -0800 (PST) Received: by mail-pj1-x102f.google.com with SMTP id gt5so5230971pjb.1; Thu, 18 Nov 2021 06:09:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=QEAi0JFFmcVSfLYqvSz9Q36wWsFfdlN527IzY0Xl91w=; b=BNYCIDqXF+9y4b/vF54ZSXcAvHm4L/wOgKJ/UAkZhYW0nozO7Zv8Bks/tDz5yrZ4OD DnPhR2IdEnwjppvTVmQkRGPuCiIl0QVMJNewSDmcbRdga9pHVy8S13vilB1txU8u87tb H7SJ4o1SKk44fDZwqtM5tZc7vZlRH9O4XBhjatHklAJQffJRieEN7xrzQn+flJq9o6LI Himzw2igxlwHQSzjflP/bLgEKcJqNWOHrS2bDE4ZsUfmNPJi7RxiPm92CcH0S0Khe/Cv qZSmJMQdLKSW80RcvtU+J0e4r4E/76uplT2xL+3pucAxz50waGVHUBU9cnZyCl7pIhyM ibZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=QEAi0JFFmcVSfLYqvSz9Q36wWsFfdlN527IzY0Xl91w=; b=u6AKamwP3PDPuLf61lj4oSCwMPWdpdT7Z/QogXQvnyyYUtRib5FyVzKrgKP+howcqd HsPoFlx5QWIq1EAYieMdKRGPHuX6qa3NtmZf86unW8IzI8Rt3nRGotoIJBUoyNpe1LWl qQpi0TFQQQoI5jM4m3wE7tsprGtsVZV+wfkZz3axCDR8fEDlDqtBYrX73QsBFh3Qlbqy JQmF90m78w6/wQaOhpRtuLZcoNXpW1qFONooA7spEHdOG1OB1sevXrOtUj53h886am6/ fyk284PuFrnkdzsG6++653Wp9eJXLVCD/jOZw93VITGqI3IgPRvnADhKYGhujUkWQXLp FFBQ== X-Gm-Message-State: AOAM5328Ang7mhU0unmwKtyIu5MoiZ0jh75Z8uhlienZoRJo5RvBNV9b 8H/vs6QLJhzq8bYGXU516Pk= X-Google-Smtp-Source: ABdhPJx0eGowQg8TSYbw2PJfbQZPFwpWcMyafhZX/7yhfmbbQRXIJXEOBIrKypVY6wqJ7VQxAwOcEw== X-Received: by 2002:a17:90b:4f44:: with SMTP id pj4mr11118669pjb.150.1637244555360; Thu, 18 Nov 2021 06:09:15 -0800 (PST) Received: from localhost.localdomain ([2406:7400:63:2c47:5ffe:fc34:61f0:f1ea]) by smtp.gmail.com with ESMTPSA id x14sm2822878pjl.27.2021.11.18.06.09.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Nov 2021 06:09:15 -0800 (PST) From: Naveen Naidu To: bhelgaas@google.com Cc: Naveen Naidu , linux-kernel-mentees@lists.linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, Sean V Kelley , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Qiuxu Zhuo Subject: [PATCH v4 20/25] PCI/PME: Use PCI_POSSIBLE_ERROR() to check read from hardware Date: Thu, 18 Nov 2021 19:33:30 +0530 Message-Id: <679ce049bccf10df3ca9ef4918ee2c3235afdaea.1637243717.git.naveennaidu479@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" An MMIO read from a PCI device that doesn't exist or doesn't respond causes a PCI error. There's no real data to return to satisfy the CPU read, so most hardware fabricates ~0 data. Use PCI_POSSIBLE_ERROR() to check the response we get when we read data from hardware. This helps unify PCI error response checking and make error checks consistent and easier to find. Compile tested only. Signed-off-by: Naveen Naidu --- drivers/pci/pcie/pme.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pcie/pme.c b/drivers/pci/pcie/pme.c index 1d0dd77fed3a..ef8ce436ead9 100644 --- a/drivers/pci/pcie/pme.c +++ b/drivers/pci/pcie/pme.c @@ -224,7 +224,7 @@ static void pcie_pme_work_fn(struct work_struct *work) break; =20 pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta); - if (rtsta =3D=3D (u32) ~0) + if (PCI_POSSIBLE_ERROR(rtsta)) break; =20 if (rtsta & PCI_EXP_RTSTA_PME) { @@ -274,7 +274,7 @@ static irqreturn_t pcie_pme_irq(int irq, void *context) spin_lock_irqsave(&data->lock, flags); pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta); =20 - if (rtsta =3D=3D (u32) ~0 || !(rtsta & PCI_EXP_RTSTA_PME)) { + if (PCI_POSSIBLE_ERROR(rtsta) || !(rtsta & PCI_EXP_RTSTA_PME)) { spin_unlock_irqrestore(&data->lock, flags); return IRQ_NONE; } --=20 2.25.1