mailbox: Add Broadcom PDC mailbox driver

Hello Rob Rice,

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

The patch a24532f8d17b: "mailbox: Add Broadcom PDC mailbox driver" from Jun 30, 2016, leads to the following Smatch complaint:

drivers/mailbox/bcm-pdc-mailbox.c:929 pdc_irq_handler()
warn: variable dereferenced before check 'pdcs' (see line 918)

drivers/mailbox/bcm-pdc-mailbox.c
917 struct pdc_state *pdcs = cookie;

   918		u32 intstatus = ioread32(pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);
                                         ^^^^^^^^^^^^^^^^^^^

Dereference.

919
920 if (intstatus & PDC_XMTINTEN_0)
921 set_bit(PDC_XMTINT_0, &pdcs->intstatus);
922 if (intstatus & PDC_RCVINTEN_0)
923 set_bit(PDC_RCVINT_0, &pdcs->intstatus);
924
925 /* Clear interrupt flags in device */
926 iowrite32(intstatus, pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);
927
928 /* Wakeup IRQ thread */
929 if (pdcs && (irq = pdcs->pdc_irq) && (intstatus & PDC_INTMASK))

                    ^^^^

Check too late to do any good. Delete?

930 return IRQ_WAKE_THREAD;
931

regards,
dan carpenter