ixgb: make sure jumbos stay enabled after reset

Currently a device reset (ethtool -r ethX) would cause the
adapter to fall back to regular MTU sizes.

Signed-off-by: Matheos Worku <[e-mail]>
Signed-off-by: Jesse Brandeburg <[e-mail]>
Signed-off-by: Auke Kok <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/net/ixgb/ixgb_main.c

···
 void
 ixgb_reset(struct ixgb_adapter *adapter)
 {
+	struct ixgb_hw *hw = &adapter->hw;
 
-	ixgb_adapter_stop(&adapter->hw);
-	if(!ixgb_init_hw(&adapter->hw))
+	ixgb_adapter_stop(hw);
+	if (!ixgb_init_hw(hw))
 		DPRINTK(PROBE, ERR, "ixgb_init_hw failed.\n");
+
+	/* restore frame size information */
+	IXGB_WRITE_REG(hw, MFS, hw->max_frame_size << IXGB_MFS_SHIFT);
+	if (hw->max_frame_size >
+	    IXGB_MAX_ENET_FRAME_SIZE_WITHOUT_FCS + ENET_FCS_LENGTH) {
+		u32 ctrl0 = IXGB_READ_REG(hw, CTRL0);
+		if (!(ctrl0 & IXGB_CTRL0_JFE)) {
+			ctrl0 |= IXGB_CTRL0_JFE;
+			IXGB_WRITE_REG(hw, CTRL0, ctrl0);
+		}
+	}
 }
 
 /**