The existing cedar driver code already has a semaphore, but is
only doing some strange and pointless manipulations with it.
Now use this semaphore to actually protect /dev/cedar_dev from
being simultaneously opened by multiple users.
When the cedar driver is already occupied, any new attempts to
open /dev/cedar_dev just block until the current user closes it.
Signed-off-by: Siarhei Siamashka <siarhei.siamas...@gmail.com>
---
drivers/media/video/sunxi/sunxi_cedar.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/media/video/sunxi/sunxi_cedar.c
b/drivers/media/video/sunxi/sunxi_cedar.c
index f30d086..64f4151 100644
--- a/drivers/media/video/sunxi/sunxi_cedar.c
+++ b/drivers/media/video/sunxi/sunxi_cedar.c
@@ -797,8 +797,7 @@ static int cedardev_open(struct inode *inode, struct file
*filp)
return -ERESTARTSYS;
}
/* init other resource here */
- devp->irq_flag = 0;
- up(&devp->sem);
+ devp->irq_flag = 0;
nonseekable_open(inode, filp);
return 0;
}
@@ -808,11 +807,9 @@ static int cedardev_release(struct inode *inode, struct
file *filp)
struct cedar_dev *devp;
devp = filp->private_data;
- if (down_interruptible(&devp->sem)) {
- return -ERESTARTSYS;
- }
+
/* release other resource here */
- devp->irq_flag = 1;
+ devp->irq_flag = 1;
up(&devp->sem);
return 0;
}
--
2.4.10
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