staging:iio: Prevent reading from buffer chrdev when device has no buffer.

Silly bug introduced during the chrdev merge series.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Jonathan Cameron 2011-09-21 11:16:02 +01:00 committed by Greg Kroah-Hartman
parent ad31d250bf
commit 30eb82f05d
3 changed files with 13 additions and 8 deletions

View File

@ -33,7 +33,7 @@ int __iio_add_chan_devattr(const char *postfix,
#ifdef CONFIG_IIO_BUFFER #ifdef CONFIG_IIO_BUFFER
struct poll_table_struct; struct poll_table_struct;
void iio_chrdev_buffer_open(struct iio_dev *indio_dev); int iio_chrdev_buffer_open(struct iio_dev *indio_dev);
void iio_chrdev_buffer_release(struct iio_dev *indio_dev); void iio_chrdev_buffer_release(struct iio_dev *indio_dev);
unsigned int iio_buffer_poll(struct file *filp, unsigned int iio_buffer_poll(struct file *filp,
@ -47,8 +47,11 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
#else #else
static inline void iio_chrdev_buffer_open(struct iio_dev *indio_dev) static inline int iio_chrdev_buffer_open(struct iio_dev *indio_dev)
{} {
return -EINVAL;
}
static inline void iio_chrdev_buffer_release(struct iio_dev *indio_dev) static inline void iio_chrdev_buffer_release(struct iio_dev *indio_dev)
{} {}

View File

@ -63,11 +63,14 @@ unsigned int iio_buffer_poll(struct file *filp,
return 0; return 0;
} }
void iio_chrdev_buffer_open(struct iio_dev *indio_dev) int iio_chrdev_buffer_open(struct iio_dev *indio_dev)
{ {
struct iio_buffer *rb = indio_dev->buffer; struct iio_buffer *rb = indio_dev->buffer;
if (rb && rb->access->mark_in_use) if (!rb)
return -EINVAL;
if (rb->access->mark_in_use)
rb->access->mark_in_use(rb); rb->access->mark_in_use(rb);
return 0;
} }
void iio_chrdev_buffer_release(struct iio_dev *indio_dev) void iio_chrdev_buffer_release(struct iio_dev *indio_dev)
@ -77,7 +80,6 @@ void iio_chrdev_buffer_release(struct iio_dev *indio_dev)
clear_bit(IIO_BUSY_BIT_POS, &rb->flags); clear_bit(IIO_BUSY_BIT_POS, &rb->flags);
if (rb->access->unmark_in_use) if (rb->access->unmark_in_use)
rb->access->unmark_in_use(rb); rb->access->unmark_in_use(rb);
} }
void iio_buffer_init(struct iio_buffer *buffer, struct iio_dev *dev_info) void iio_buffer_init(struct iio_buffer *buffer, struct iio_dev *dev_info)

View File

@ -1065,8 +1065,8 @@ static int iio_chrdev_open(struct inode *inode, struct file *filp)
struct iio_dev *dev_info = container_of(inode->i_cdev, struct iio_dev *dev_info = container_of(inode->i_cdev,
struct iio_dev, chrdev); struct iio_dev, chrdev);
filp->private_data = dev_info; filp->private_data = dev_info;
iio_chrdev_buffer_open(dev_info);
return 0; return iio_chrdev_buffer_open(dev_info);
} }
/** /**