spi: Always check complete callback before calling it

Since commit 1e25cd4729bd "spi: Do not require a completion", this checking is
required to prevent NULL pointer dereference.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/spi/spi-sh.c b/drivers/spi/spi-sh.c
index f6f2c7010177..03edf5ed0e9f 100644
--- a/drivers/spi/spi-sh.c
+++ b/drivers/spi/spi-sh.c
@@ -322,7 +322,8 @@ static void spi_sh_work(struct work_struct *work)
                 spin_lock_irqsave(&ss->lock, flags);
 
                 mesg->status = 0;
-                mesg->complete(mesg->context);
+                if (mesg->complete)
+                        mesg->complete(mesg->context);
         }
 
         clear_fifo(ss);
@@ -340,7 +341,8 @@ static void spi_sh_work(struct work_struct *work)
 
  error:
         mesg->status = ret;
-        mesg->complete(mesg->context);
+        if (mesg->complete)
+                mesg->complete(mesg->context);
 
         spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
                          SPI_SH_CR1);