drivers/net: support hdlc function for QE-UCC

Hello Zhao Qiang,

This is a semi-automatic email about new static checker warnings.

The patch c19b6d246a35: "drivers/net: support hdlc function for QE-UCC" from Jun 6, 2016, leads to the following Smatch complaint:

drivers/net/wan/fsl_ucc_hdlc.c:707 uhdlc_memclean()

	 warn: variable dereferenced before check 'priv->ucc_pram' (see line 686)

drivers/net/wan/fsl_ucc_hdlc.c
685 {
686 qe_muram_free(priv->ucc_pram->riptr);

   687		qe_muram_free(priv->ucc_pram->tiptr);
                              ^^^^^^^^^^^^^^

Dereference.

688
689 if (priv->rx_bd_base) {
690 dma_free_coherent(priv->dev,
691 RX_BD_RING_LEN * sizeof(struct qe_bd),
692 priv->rx_bd_base, priv->dma_rx_bd);
693
694 priv->rx_bd_base = NULL;
695 priv->dma_rx_bd = 0;
696 }
697
698 if (priv->tx_bd_base) {
699 dma_free_coherent(priv->dev,
700 TX_BD_RING_LEN * sizeof(struct qe_bd),
701 priv->tx_bd_base, priv->dma_tx_bd);
702
703 priv->tx_bd_base = NULL;
704 priv->dma_tx_bd = 0;
705 }
706

   707		if (priv->ucc_pram) {
                    ^^^^^^^^^^^^^^

Checked too late.

   708			qe_muram_free(priv->ucc_pram_offset);
   709			priv->ucc_pram = NULL;

regards,
dan carpenter