From patchwork Fri Jul 31 11:02:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Saheed O. Bolarinwa" X-Patchwork-Id: 11694747 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B195B138C for ; Fri, 31 Jul 2020 12:02:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9978622CA1 for ; Fri, 31 Jul 2020 12:02:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="M6Y0jv5k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733012AbgGaMCX (ORCPT ); Fri, 31 Jul 2020 08:02:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732699AbgGaMCW (ORCPT ); Fri, 31 Jul 2020 08:02:22 -0400 Received: from mail-ej1-x644.google.com (mail-ej1-x644.google.com [IPv6:2a00:1450:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 652AAC061574; Fri, 31 Jul 2020 05:02:22 -0700 (PDT) Received: by mail-ej1-x644.google.com with SMTP id qc22so16378770ejb.4; Fri, 31 Jul 2020 05:02:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=0s8kQrogwdlSPLZApHKOPIg76Pp1CNTA9YznKKgGPck=; b=M6Y0jv5kDqUnaX/yd/T2xgMQt71taFc83qH0hNkDJSCO82eBpAd0hnmaZzXzH8JwwR QxnHOUFXM4WOTonZWpymDce5CueUtu5cPdmXzfF3QkrFwjTonyaSBB6/OFutNKWXXJl7 1jUDYkKMxsmMDhL2Zw4OcJ1xStjLUKRpOJXm5Y9RjchXLuWxHlaZ4NjkFERXie4cqi+O OqAUwBdHmMok6y4FmBJihc5eH+MTABnbOjG2wVrZs5mQO/rZvl7GoIwILp5r9rZkXKaj I1ZZYBXCyxy0zsS5imx/7/w6t7tKz/PDc+l5Py3ZaKD6QtvvAyfi+GgIxAJ99ngBWThA 2OYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=0s8kQrogwdlSPLZApHKOPIg76Pp1CNTA9YznKKgGPck=; b=V7QYWryoK4+e4eZVv1xqAbRKBVzC3neKD4xzKAi7IWfFtWvTIw4riOgMzPQ/XABLDb Q44QNADShZSWV+d8eu/fS45awaQ8Zr+VLpIDFOiWb0auyWkfy3s6wVGbhM36vREVYQ/8 fNibDIYcTuKsme6vHrK8KXPxsv1t1R7oP6Hut59jdpoaTSHSNTPFmDkV+sfRC0ZhirUK wHdEUJgqIdO28U+NoPEbEkX5htcWNWV2SYpurXP61hTuSt28cPsk9TguUzJtvjpJAV10 PkEilVeEjs3JnSNTqDr4hyvbvIt8UgQY+NFqeDmLg6ZZL2h1QTSRckqqKT5zKoT4E/xw 6sBA== X-Gm-Message-State: AOAM532+tpeYjNk4BAVYrgthFq+aZXZ+S75AVLcN925cAwPwUS8f0Dwi hCeIIRqmNDgMR4zCfpeI685Vtgz8yBowbw== X-Google-Smtp-Source: ABdhPJz45zbOZzboFeAodzV6Jdd70KawW/kH4Nt1N7OyBQuz8phrmzy5Ee9QL5qqaAtYtkYbQgzHiA== X-Received: by 2002:a17:906:1c0e:: with SMTP id k14mr3597814ejg.479.1596196941171; Fri, 31 Jul 2020 05:02:21 -0700 (PDT) Received: from net.saheed (95C84E0A.dsl.pool.telekom.hu. [149.200.78.10]) by smtp.gmail.com with ESMTPSA id j5sm9091734ejk.87.2020.07.31.05.02.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 31 Jul 2020 05:02:20 -0700 (PDT) From: "Saheed O. Bolarinwa" To: helgaas@kernel.org, "David S. Miller" , Kalle Valo , Jakub Kicinski Cc: "Saheed O. Bolarinwa" , bjorn@helgaas.com, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, QCA ath9k Development , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v4 03/12] ath9k: Check if pcie_capability_read_*() reads ~0 Date: Fri, 31 Jul 2020 13:02:31 +0200 Message-Id: <20200731110240.98326-4-refactormyself@gmail.com> X-Mailer: git-send-email 2.18.4 In-Reply-To: <20200731110240.98326-1-refactormyself@gmail.com> References: <20200731110240.98326-1-refactormyself@gmail.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On failure pcie_capability_read_dword() sets it's last parameter, val to 0. However, with Patch 12/12, it is possible that val is set to ~0 on failure. This would introduce a bug because (x & x) == (~0 & x). Since ~0 is an invalid value here, Add an extra check for ~0 to the if condition to ensure success. Suggested-by: Bjorn Helgaas Signed-off-by: Saheed O. Bolarinwa --- drivers/net/wireless/ath/ath9k/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath9k/pci.c b/drivers/net/wireless/ath/ath9k/pci.c index f3461b193c7a..f02b243befef 100644 --- a/drivers/net/wireless/ath/ath9k/pci.c +++ b/drivers/net/wireless/ath/ath9k/pci.c @@ -867,7 +867,8 @@ static void ath_pci_aspm_init(struct ath_common *common) pci_read_config_dword(pdev, 0x70c, &ah->config.aspm_l1_fix); pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &aspm); - if (aspm & (PCI_EXP_LNKCTL_ASPM_L0S | PCI_EXP_LNKCTL_ASPM_L1)) { + if ((aspm != (u16)~0) && + (aspm & (PCI_EXP_LNKCTL_ASPM_L0S | PCI_EXP_LNKCTL_ASPM_L1))) { ah->aspm_enabled = true; /* Initialize PCIe PM and SERDES registers. */ ath9k_hw_configpcipowersave(ah, false);