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From:   =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
To:     linux-pci@vger.kernel.org, Bjorn Helgaas <helgaas@kernel.org>,
        Rob Herring <robh@kernel.org>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Lukas Wunner <lukas@wunner.de>,
        Heiner Kallweit <hkallweit1@gmail.com>, nic_swsd@realtek.com,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
Subject: [PATCH 14/17] r8169: Use pcie_lnkctl_clear_and_set() for changing LNKCTL
Date:   Thu, 11 May 2023 16:14:38 +0300
Message-Id: <20230511131441.45704-15-ilpo.jarvinen@linux.intel.com>
In-Reply-To: <20230511131441.45704-1-ilpo.jarvinen@linux.intel.com>
References: <20230511131441.45704-1-ilpo.jarvinen@linux.intel.com>
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Don't assume that only the driver would be accessing LNKCTL. ASPM
policy changes can trigger write to LNKCTL outside of driver's control.

Use pcie_lnkctl_clear_and_set() which does proper locking to avoid
losing concurrent updates to the register value.

Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index a7e376e7e689..c0294a833681 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -2686,14 +2686,12 @@ static void __rtl_ephy_init(struct rtl8169_private *tp,
 
 static void rtl_disable_clock_request(struct rtl8169_private *tp)
 {
-	pcie_capability_clear_word(tp->pci_dev, PCI_EXP_LNKCTL,
-				   PCI_EXP_LNKCTL_CLKREQ_EN);
+	pcie_lnkctl_clear_and_set(tp->pci_dev, PCI_EXP_LNKCTL_CLKREQ_EN, 0);
 }
 
 static void rtl_enable_clock_request(struct rtl8169_private *tp)
 {
-	pcie_capability_set_word(tp->pci_dev, PCI_EXP_LNKCTL,
-				 PCI_EXP_LNKCTL_CLKREQ_EN);
+	pcie_lnkctl_clear_and_set(tp->pci_dev, 0, PCI_EXP_LNKCTL_CLKREQ_EN);
 }
 
 static void rtl_pcie_state_l2l3_disable(struct rtl8169_private *tp)
-- 
2.30.2