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[84.0.113.134]) by smtp.gmail.com with ESMTPSA id w3sm11838938edq.65.2020.07.13.09.55.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2020 09:55:11 -0700 (PDT) From: "Saheed O. Bolarinwa" To: skhan@linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org, QCA ath9k Development , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Cc: Bolarinwa Olayemi Saheed , Kalle Valo Subject: [PATCH 3/14 v3] ath9k: Check the return value of pcie_capability_read_*() Date: Mon, 13 Jul 2020 19:55:26 +0200 Message-Id: <20200713175529.29715-2-refactormyself@gmail.com> X-Mailer: git-send-email 2.18.2 In-Reply-To: <20200713175529.29715-1-refactormyself@gmail.com> References: <20200713175529.29715-1-refactormyself@gmail.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Bolarinwa Olayemi Saheed On failure pcie_capability_read_dword() sets it's last parameter, val to 0. However, with Patch 14/14, it is possible that val is set to ~0 on failure. This would introduce a bug because (x & x) == (~0 & x). This bug can be avoided without changing the function's behaviour if the return value of pcie_capability_read_dword is checked to confirm success. Check the return value of pcie_capability_read_dword() to ensure success. Suggested-by: Bjorn Helgaas Signed-off-by: Bolarinwa Olayemi Saheed --- drivers/net/wireless/ath/ath9k/pci.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/pci.c b/drivers/net/wireless/ath/ath9k/pci.c index f3461b193c7a..cff9af3af38d 100644 --- a/drivers/net/wireless/ath/ath9k/pci.c +++ b/drivers/net/wireless/ath/ath9k/pci.c @@ -825,6 +825,7 @@ static void ath_pci_aspm_init(struct ath_common *common) struct pci_dev *pdev = to_pci_dev(sc->dev); struct pci_dev *parent; u16 aspm; + int ret; if (!ah->is_pciexpress) return; @@ -866,8 +867,8 @@ static void ath_pci_aspm_init(struct ath_common *common) if (AR_SREV_9462(ah)) 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)) { + ret = pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &aspm); + if (!ret && (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);