6.4-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 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@wunner.de Fixes: eabe8e5e88f5 ("net/mlx5: Handle sync reset now event") Link: https://lore.kernel.org/r/20230717120503.15276-8-ilpo.jarvinen@linux.intel.c... Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Moshe Shemesh moshe@nvidia.com Reviewed-by: Simon Horman simon.horman@corigine.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c index 50022e7565f14..f202150a5093c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c @@ -332,16 +332,11 @@ 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, ®16); - 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;