mailbox: bcm-pdc: potential NULL dereference in pdc_shutdown()

We can't pass NULL pointers to pdc_ring_free() so I moved the check for
NULL.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/mailbox/bcm-pdc-mailbox.c b/drivers/mailbox/bcm-pdc-mailbox.c
index cbe0c1ee4ba9..c56d4d0b2307 100644
--- a/drivers/mailbox/bcm-pdc-mailbox.c
+++ b/drivers/mailbox/bcm-pdc-mailbox.c
@@ -1191,10 +1191,11 @@ static void pdc_shutdown(struct mbox_chan *chan)
 {
         struct pdc_state *pdcs = chan->con_priv;
 
-        if (pdcs)
-                dev_dbg(&pdcs->pdev->dev,
-                        "Shutdown mailbox channel for PDC %u", pdcs->pdc_idx);
+        if (!pdcs)
+                return;
 
+        dev_dbg(&pdcs->pdev->dev,
+                "Shutdown mailbox channel for PDC %u", pdcs->pdc_idx);
         pdc_ring_free(pdcs);
 }