Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6

[pandora-kernel.git] / drivers / spi / spi.c

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 89769ce..682a6a4 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -457,10 +457,11 @@ done:
 EXPORT_SYMBOL_GPL(spi_register_master);
 
 
-static int __unregister(struct device *dev, void *unused)
+static int __unregister(struct device *dev, void *master_dev)
 {
        /* note: before about 2.6.14-rc1 this would corrupt memory: */
-       spi_unregister_device(to_spi_device(dev));
+       if (dev != master_dev)
+               spi_unregister_device(to_spi_device(dev));
        return 0;
 }
 
@@ -478,11 +479,21 @@ void spi_unregister_master(struct spi_master *master)
 {
        int dummy;
 
-       dummy = device_for_each_child(master->dev.parent, NULL, __unregister);
+       dummy = device_for_each_child(master->dev.parent, &master->dev,
+                                       __unregister);
        device_unregister(&master->dev);
 }
 EXPORT_SYMBOL_GPL(spi_unregister_master);
 
+static int __spi_master_match(struct device *dev, void *data)
+{
+       struct spi_master *m;
+       u16 *bus_num = data;
+
+       m = container_of(dev, struct spi_master, dev);
+       return m->bus_num == *bus_num;
+}
+
 /**
  * spi_busnum_to_master - look up master associated with bus_num
  * @bus_num: the master's bus number
@@ -497,17 +508,12 @@ struct spi_master *spi_busnum_to_master(u16 bus_num)
 {
        struct device           *dev;
        struct spi_master       *master = NULL;
-       struct spi_master       *m;
-
-       down(&spi_master_class.sem);
-       list_for_each_entry(dev, &spi_master_class.children, node) {
-               m = container_of(dev, struct spi_master, dev);
-               if (m->bus_num == bus_num) {
-                       master = spi_master_get(m);
-                       break;
-               }
-       }
-       up(&spi_master_class.sem);
+
+       dev = class_find_device(&spi_master_class, &bus_num,
+                               __spi_master_match);
+       if (dev)
+               master = container_of(dev, struct spi_master, dev);
+       /* reference got in class_find_device */
        return master;
 }
 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
@@ -539,10 +545,7 @@ static void spi_complete(void *arg)
  * Also, the caller is guaranteeing that the memory associated with the
  * message will not be freed before this call returns.
  *
- * The return value is a negative error code if the message could not be
- * submitted, else zero.  When the value is zero, then message->status is
- * also defined;  it's the completion code for the transfer, either zero
- * or a negative error code from the controller driver.
+ * It returns zero on success, else a negative error code.
  */
 int spi_sync(struct spi_device *spi, struct spi_message *message)
 {
@@ -552,8 +555,10 @@ int spi_sync(struct spi_device *spi, struct spi_message *message)
        message->complete = spi_complete;
        message->context = &done;
        status = spi_async(spi, message);
-       if (status == 0)
+       if (status == 0) {
                wait_for_completion(&done);
+               status = message->status;
+       }
        message->context = NULL;
        return status;
 }
@@ -587,7 +592,7 @@ 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;
@@ -613,7 +618,7 @@ 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;
@@ -626,13 +631,11 @@ int spi_write_then_read(struct spi_device *spi,
 
        /* do the i/o */
        status = spi_sync(spi, &message);
-       if (status == 0) {
+       if (status == 0)
                memcpy(rxbuf, x[1].rx_buf, n_rx);
-               status = message.status;
-       }
 
        if (x[0].tx_buf == buf)
-               up(&lock);
+               mutex_unlock(&lock);
        else
                kfree(local_buf);