Commit 30de8725 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
Browse files

net/mlx5: Use RMW accessors for changing LNKCTL 



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: default avatarLukas Wunner <lukas@wunner.de>
Fixes: eabe8e5e ("net/mlx5: Handle sync reset now event")
Link: https://lore.kernel.org/r/20230717120503.15276-8-ilpo.jarvinen@linux.intel.com


Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarMoshe Shemesh <moshe@nvidia.com>
Reviewed-by: default avatarSimon Horman <simon.horman@corigine.com>
parent 7189576e

drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c

+2 −7
Original line number Diff line number Diff line
@@ -384,16 +384,11 @@ 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;