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>
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index b31f443..6ca07c9 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -589,7 +589,7 @@
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 @@
}
/* ... 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 @@
}
if (x[0].tx_buf == buf)
- up(&lock);
+ mutex_unlock(&lock);
else
kfree(local_buf);