staging: most: remove stacked_mbo

This patch makes use of kfifo_peek and kfifo_skip, which renders the
variable stacked_mbo useless. It is therefore removed.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/aim-cdev/cdev.c b/drivers/staging/most/aim-cdev/cdev.c
index d9c3f56..0ee2f08 100644 (file)
--- a/drivers/staging/most/aim-cdev/cdev.c
+++ b/drivers/staging/most/aim-cdev/cdev.c
@@ -41,7 +41,6 @@ struct aim_channel {
        unsigned int channel_id;
        dev_t devno;
        size_t mbo_offs;
-       struct mbo *stacked_mbo;
        DECLARE_KFIFO_PTR(fifo, typeof(struct mbo *));
        int access_ref;
        struct list_head list;
@@ -87,9 +86,6 @@ static void stop_channel(struct aim_channel *c)
 
        while (kfifo_out((struct kfifo *)&c->fifo, &mbo, 1))
                most_put_mbo(mbo);
-       if (c->stacked_mbo)
-               most_put_mbo(c->stacked_mbo);
-       c->stacked_mbo = NULL;
        most_stop_channel(c->iface, c->channel_id, &cdev_aim);
 }
 
@@ -143,6 +139,7 @@ static int aim_open(struct inode *inode, struct file *filp)
                return -EBUSY;
        }
 
+       c->mbo_offs = 0;
        ret = most_start_channel(c->iface, c->channel_id, &cdev_aim);
        if (!ret)
                c->access_ref = 1;
@@ -249,11 +246,7 @@ aim_read(struct file *filp, char __user *buf, size_t count, loff_t *offset)
        struct aim_channel *c = filp->private_data;
 
        mutex_lock(&c->io_mutex);
-       if (c->stacked_mbo) {
-               mbo = c->stacked_mbo;
-               goto start_copy;
-       }
-       while ((!kfifo_out(&c->fifo, &mbo, 1)) && (c->dev)) {
+       while (c->dev && !kfifo_peek(&c->fifo, &mbo)) {
                mutex_unlock(&c->io_mutex);
                if (filp->f_flags & O_NONBLOCK)
                        return -EAGAIN;
@@ -263,9 +256,7 @@ aim_read(struct file *filp, char __user *buf, size_t count, loff_t *offset)
                        return -ERESTARTSYS;
                mutex_lock(&c->io_mutex);
        }
-       c->stacked_mbo = mbo;
 
-start_copy:
        /* make sure we don't submit to gone devices */
        if (unlikely(!c->dev)) {
                mutex_unlock(&c->io_mutex);
@@ -284,9 +275,9 @@ start_copy:
 
        c->mbo_offs += copied;
        if (c->mbo_offs >= mbo->processed_length) {
+               kfifo_skip(&c->fifo);
                most_put_mbo(mbo);
                c->mbo_offs = 0;
-               c->stacked_mbo = NULL;
        }
        mutex_unlock(&c->io_mutex);
        return copied;
@@ -466,7 +457,6 @@ static int aim_probe(struct most_interface *iface, int channel_id,
        c->iface = iface;
        c->cfg = cfg;
        c->channel_id = channel_id;
-       c->mbo_offs = 0;
        c->access_ref = 0;
        spin_lock_init(&c->unlink);
        INIT_KFIFO(c->fifo);