SPI: use mutex not semaphore

Make spi_write_then_read() use a mutex not a binary semaphore.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index b31f4431849b..6ca07c9929e6 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -589,7 +589,7 @@ int spi_write_then_read(struct spi_device *spi,
                 const u8 *txbuf, unsigned n_tx,
                 u8 *rxbuf, unsigned n_rx)
 {
-        static DECLARE_MUTEX(lock);
+        static DEFINE_MUTEX(lock);
 
         int                     status;
         struct spi_message      message;
@@ -615,7 +615,7 @@ int spi_write_then_read(struct spi_device *spi,
         }
 
         /* ... unless someone else is using the pre-allocated buffer */
-        if (down_trylock(&lock)) {
+        if (!mutex_trylock(&lock)) {
                 local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
                 if (!local_buf)
                         return -ENOMEM;
@@ -634,7 +634,7 @@ int spi_write_then_read(struct spi_device *spi,
         }
 
         if (x[0].tx_buf == buf)
-                up(&lock);
+                mutex_unlock(&lock);
         else
                 kfree(local_buf);