[PATCH v3 03/10] PCI: pciehp: Use RMW accessors for changing LNKCTL

Ilpo Järvinen
2023-06-20T13:47:16Z

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>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
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