[PATCH net-next 2/5] net/mlx5: fw reset, check bridge accessibility at earlier stage

[Tariq Toukan <tariqt@xxxxxxxxxx>]

From: Amir Tzin <amirtz@xxxxxxxxxx>

Currently, mlx5_is_reset_now_capable() checks whether the pci bridge is
accessible only on bridge hot plug capability check.  If the pci bridge
is not accessible, reset now will fail regardless of bridge hotplug
capability. Move this check to function mlx5_is_reset_now_capable()
which, in such case, aborts the reset and does so in the request phase
instead of the reset now phase.

Signed-off-by: Aya Levin <ayal@xxxxxxxxxx>
Signed-off-by: Moshe Shemesh <moshe@xxxxxxxxxx>
Signed-off-by: Amir Tzin <amirtz@xxxxxxxxxx>
Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxx>
---
 .../net/ethernet/mellanox/mlx5/core/fw_reset.c    | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
index 566710d34a7b..6830a49fe682 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c
@@ -345,15 +345,12 @@ static void mlx5_fw_live_patch_event(struct work_struct *work)
 }
 
 #if IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)
-static int mlx5_check_hotplug_interrupt(struct mlx5_core_dev *dev)
+static int mlx5_check_hotplug_interrupt(struct mlx5_core_dev *dev,
+					struct pci_dev *bridge)
 {
-	struct pci_dev *bridge = dev->pdev->bus->self;
 	u16 reg16;
 	int err;
 
-	if (!bridge)
-		return -EOPNOTSUPP;
-
 	err = pcie_capability_read_word(bridge, PCI_EXP_SLTCTL, &reg16);
 	if (err)
 		return err;
@@ -416,9 +413,15 @@ static int mlx5_check_dev_ids(struct mlx5_core_dev *dev, u16 dev_id)
 static bool mlx5_is_reset_now_capable(struct mlx5_core_dev *dev,
 				      u8 reset_method)
 {
+	struct pci_dev *bridge = dev->pdev->bus->self;
 	u16 dev_id;
 	int err;
 
+	if (!bridge) {
+		mlx5_core_warn(dev, "PCI bus bridge is not accessible\n");
+		return false;
+	}
+
 	if (!MLX5_CAP_GEN(dev, fast_teardown)) {
 		mlx5_core_warn(dev, "fast teardown is not supported by firmware\n");
 		return false;
@@ -426,7 +429,7 @@ static bool mlx5_is_reset_now_capable(struct mlx5_core_dev *dev,
 
 #if IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)
 	if (reset_method != MLX5_MFRL_REG_PCI_RESET_METHOD_HOT_RESET) {
-		err = mlx5_check_hotplug_interrupt(dev);
+		err = mlx5_check_hotplug_interrupt(dev, bridge);
 		if (err)
 			return false;
 	}
-- 
2.31.1