diff options
Diffstat (limited to 'drivers/iio/industrialio-buffer.c')
| -rw-r--r-- | drivers/iio/industrialio-buffer.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 6eee1b044c60..d7e908acb480 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -71,8 +71,9 @@ static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf, if (avail >= to_wait) { /* force a flush for non-blocking reads */ - if (!to_wait && !avail && to_flush) - iio_buffer_flush_hwfifo(indio_dev, buf, to_flush); + if (!to_wait && avail < to_flush) + iio_buffer_flush_hwfifo(indio_dev, buf, + to_flush - avail); return true; } @@ -90,9 +91,16 @@ static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf, /** * iio_buffer_read_first_n_outer() - chrdev read for buffer access + * @filp: File structure pointer for the char device + * @buf: Destination buffer for iio buffer read + * @n: First n bytes to read + * @f_ps: Long offset provided by the user as a seek position * * This function relies on all buffer implementations having an * iio_buffer as their first element. + * + * Return: negative values corresponding to error codes or ret != 0 + * for ending the reading activity **/ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, size_t n, loff_t *f_ps) @@ -100,8 +108,7 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, struct iio_dev *indio_dev = filp->private_data; struct iio_buffer *rb = indio_dev->buffer; size_t datum_size; - size_t to_wait = 0; - size_t to_read; + size_t to_wait; int ret; if (!indio_dev->info) @@ -119,14 +126,14 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, if (!datum_size) return 0; - to_read = min_t(size_t, n / datum_size, rb->watermark); - - if (!(filp->f_flags & O_NONBLOCK)) - to_wait = to_read; + if (filp->f_flags & O_NONBLOCK) + to_wait = 0; + else + to_wait = min_t(size_t, n / datum_size, rb->watermark); do { ret = wait_event_interruptible(rb->pollq, - iio_buffer_ready(indio_dev, rb, to_wait, to_read)); + iio_buffer_ready(indio_dev, rb, to_wait, n / datum_size)); if (ret) return ret; @@ -143,6 +150,12 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, /** * iio_buffer_poll() - poll the buffer to find out if it has data + * @filp: File structure pointer for device access + * @wait: Poll table structure pointer for which the driver adds + * a wait queue + * + * Return: (POLLIN | POLLRDNORM) if data is available for reading + * or 0 for other cases */ unsigned int iio_buffer_poll(struct file *filp, struct poll_table_struct *wait) @@ -151,7 +164,7 @@ unsigned int iio_buffer_poll(struct file *filp, struct iio_buffer *rb = indio_dev->buffer; if (!indio_dev->info) - return -ENODEV; + return 0; poll_wait(filp, &rb->pollq, wait); if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0)) @@ -1136,7 +1149,7 @@ int iio_scan_mask_query(struct iio_dev *indio_dev, EXPORT_SYMBOL_GPL(iio_scan_mask_query); /** - * struct iio_demux_table() - table describing demux memcpy ops + * struct iio_demux_table - table describing demux memcpy ops * @from: index to copy from * @to: index to copy to * @length: how many bytes to copy |