In order to dump the FECs registers the clocks have to be ticking,
otherwise a data abort occurs.  Add calls to runtime PM so they are
enabled and later disabled.
Fixes: e8fcfcd5684a ("net: fec: optimize the clock management to save power")
Reported-by: Chris Healy <Chris.Healy@zii.aero>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
 {
        struct fec_enet_private *fep = netdev_priv(ndev);
        u32 __iomem *theregs = (u32 __iomem *)fep->hwp;
+       struct device *dev = &fep->pdev->dev;
        u32 *buf = (u32 *)regbuf;
        u32 i, off;
+       int ret;
+
+       ret = pm_runtime_get_sync(dev);
+       if (ret < 0)
+               return;
 
        regs->version = fec_enet_register_version;
 
                off >>= 2;
                buf[off] = readl(&theregs[off]);
        }
+
+       pm_runtime_mark_last_busy(dev);
+       pm_runtime_put_autosuspend(dev);
 }
 
 static int fec_enet_get_ts_info(struct net_device *ndev,