Commit 3b065e91 authored Jul 17, 2023 by Ilpo Järvinen Committed by Greg Kroah-Hartman Sep 23, 2023

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: 7f822999 ("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>

parent aff469bd

drivers/pci/hotplug/pciehp_hpc.c

+3 −9

Original line number	Diff line number	Diff line
		@@ -298,17 +298,11 @@ 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;
		}