PCI: pciehp: Use RMW accessors for changing LNKCTL

[ Upstream commit 5f75f96c61039151c193775d776fde42477eace1 ]

As hotplug is not the only driver touching LNKCTL, use the RMW capability
accessor which handles concurrent changes correctly.

Suggested-by: Lukas Wunner <lukas@wunner.de>
Fixes: 7f822999e12a ("PCI: pciehp: Add Disable/enable link functions")
Link: https://lore.kernel.org/r/20230717120503.15276-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index c2dd297d4007b42ec36662d2ab6e6fff1a9a3cc0..2ec015d1f671052ee9f17d0a7e19b4cc8e74ff08 100644 (file)
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -338,17 +338,11 @@ int pciehp_check_link_status(struct controller *ctrl)
 static int __pciehp_link_set(struct controller *ctrl, bool enable)
 {
        struct pci_dev *pdev = ctrl_dev(ctrl);
-       u16 lnk_ctrl;
 
-       pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnk_ctrl);
+       pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL,
+                                          PCI_EXP_LNKCTL_LD,
+                                          enable ? 0 : PCI_EXP_LNKCTL_LD);
 
-       if (enable)
-               lnk_ctrl &= ~PCI_EXP_LNKCTL_LD;
-       else
-               lnk_ctrl |= PCI_EXP_LNKCTL_LD;
-
-       pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnk_ctrl);
-       ctrl_dbg(ctrl, "%s: lnk_ctrl = %x\n", __func__, lnk_ctrl);
        return 0;
 }