Patch "net/mlx5: Use RMW accessors for changing LNKCTL" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net/mlx5: Use RMW accessors for changing LNKCTL

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-mlx5-use-rmw-accessors-for-changing-lnkctl.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c9c96ca184da361080f4770e77270fa22d830183
Author: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Date:   Mon Jul 17 15:04:59 2023 +0300

    net/mlx5: Use RMW accessors for changing LNKCTL
    
    [ Upstream commit 30de872537bda526664d7a20b646adfb3e7ce6e6 ]
    
    Don't assume that only the driver would be accessing LNKCTL of the upstream
    bridge. ASPM policy changes can trigger write to LNKCTL outside of driver's
    control.
    
    Use RMW capability accessors which do proper locking to avoid losing
    concurrent updates to the register value.
    
    Suggested-by: Lukas Wunner <lukas@xxxxxxxxx>
    Fixes: eabe8e5e88f5 ("net/mlx5: Handle sync reset now event")
    Link: https://lore.kernel.org/r/20230717120503.15276-8-ilpo.jarvinen@xxxxxxxxxxxxxxx
    Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
    Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
    Reviewed-by: Moshe Shemesh <moshe@xxxxxxxxxx>
    Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
index 8c2b249949b97..8ed1549a99c42 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
@@ -274,16 +274,11 @@ static int mlx5_pci_link_toggle(struct mlx5_core_dev *dev)
 		pci_cfg_access_lock(sdev);
 	}
 	/* PCI link toggle */
-	err = pci_read_config_word(bridge, cap + PCI_EXP_LNKCTL, &reg16);
-	if (err)
-		return err;
-	reg16 |= PCI_EXP_LNKCTL_LD;
-	err = pci_write_config_word(bridge, cap + PCI_EXP_LNKCTL, reg16);
+	err = pcie_capability_set_word(bridge, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_LD);
 	if (err)
 		return err;
 	msleep(500);
-	reg16 &= ~PCI_EXP_LNKCTL_LD;
-	err = pci_write_config_word(bridge, cap + PCI_EXP_LNKCTL, reg16);
+	err = pcie_capability_clear_word(bridge, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_LD);
 	if (err)
 		return err;