mlxsw: pci: Fix reset wait for SwitchX2

SwitchX2 firmware does not implement reset done yet. Moreover, when
busy-polled for ready magic, that slows down firmware and reset takes
longer than the defined timeout, causing initialization to fail.
So restore the previous behaviour and just sleep in this case.

Fixes: 233fa44b ("mlxsw: pci: Implement reset done check")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/pci.c

@@ -1838,11 +1838,17 @@ static const struct mlxsw_bus mlxsw_pci_bus = {
 	.cmd_exec		= mlxsw_pci_cmd_exec,
 };
 
-static int mlxsw_pci_sw_reset(struct mlxsw_pci *mlxsw_pci)
+static int mlxsw_pci_sw_reset(struct mlxsw_pci *mlxsw_pci,
+			      const struct pci_device_id *id)
 {
 	unsigned long end;
 
 	mlxsw_pci_write32(mlxsw_pci, SW_RESET, MLXSW_PCI_SW_RESET_RST_BIT);
+	if (id->device == PCI_DEVICE_ID_MELLANOX_SWITCHX2) {
+		msleep(MLXSW_PCI_SW_RESET_TIMEOUT_MSECS);
+		return 0;
+	}
+
 	wmb(); /* reset needs to be written before we read control register */
 	end = jiffies + msecs_to_jiffies(MLXSW_PCI_SW_RESET_TIMEOUT_MSECS);
 	do {
@@ -1909,7 +1915,7 @@ static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	mlxsw_pci->pdev = pdev;
 	pci_set_drvdata(pdev, mlxsw_pci);
 
-	err = mlxsw_pci_sw_reset(mlxsw_pci);
+	err = mlxsw_pci_sw_reset(mlxsw_pci, id);
 	if (err) {
 		dev_err(&pdev->dev, "Software reset failed\n");
 		goto err_sw_reset;