[PATCH v2 2/9] PCI: pciehp: Use RMW accessors for changing LNKCTL - Linux-stable-mirror

17 May 2023

As hotplug is not the only driver touching LNKCTL, use the RMW
capability accessor which handles concurrent changes correctly.
Fixes: 7f822999e12a ("PCI: pciehp: Add Disable/enable link functions")
Suggested-by: Lukas Wunner lukas@wunner.de
Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
Cc: stable@vger.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 f8c70115b691..26623e2884a3 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -332,17 +332,11 @@ 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 ? PCI_EXP_LNKCTL_LD : 0);
-	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;
 }
-- 
2.30.2


    