4.14-stable review patch. If anyone has any objections, please let me know.
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From: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
[ 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.c... 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 --- drivers/pci/hotplug/pciehp_hpc.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index c2dd297d4007b..2ec015d1f6710 100644 --- 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; }