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path: root/drivers/iio/kfifo_buf.c
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Diffstat (limited to 'drivers/iio/kfifo_buf.c')
-rw-r--r--drivers/iio/kfifo_buf.c31
1 files changed, 23 insertions, 8 deletions
diff --git a/drivers/iio/kfifo_buf.c b/drivers/iio/kfifo_buf.c
index 6bf9d05f4841..5bc5c860e9ca 100644
--- a/drivers/iio/kfifo_buf.c
+++ b/drivers/iio/kfifo_buf.c
@@ -6,6 +6,7 @@
#include <linux/kfifo.h>
#include <linux/mutex.h>
#include <linux/iio/kfifo_buf.h>
+#include <linux/sched.h>
struct iio_kfifo {
struct iio_buffer buffer;
@@ -22,7 +23,8 @@ static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
return -EINVAL;
__iio_update_buffer(&buf->buffer, bytes_per_datum, length);
- return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL);
+ return __kfifo_alloc((struct __kfifo *)&buf->kf, length,
+ bytes_per_datum, GFP_KERNEL);
}
static int iio_request_update_kfifo(struct iio_buffer *r)
@@ -35,6 +37,7 @@ static int iio_request_update_kfifo(struct iio_buffer *r)
kfifo_free(&buf->kf);
ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
buf->buffer.length);
+ r->stufftoread = false;
error_ret:
return ret;
}
@@ -81,6 +84,9 @@ static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
static int iio_set_length_kfifo(struct iio_buffer *r, int length)
{
+ /* Avoid an invalid state */
+ if (length < 2)
+ length = 2;
if (r->length != length) {
r->length = length;
iio_mark_update_needed_kfifo(r);
@@ -89,14 +95,16 @@ static int iio_set_length_kfifo(struct iio_buffer *r, int length)
}
static int iio_store_to_kfifo(struct iio_buffer *r,
- u8 *data,
- s64 timestamp)
+ u8 *data)
{
int ret;
struct iio_kfifo *kf = iio_to_kfifo(r);
- ret = kfifo_in(&kf->kf, data, r->bytes_per_datum);
- if (ret != r->bytes_per_datum)
+ ret = kfifo_in(&kf->kf, data, 1);
+ if (ret != 1)
return -EBUSY;
+ r->stufftoread = true;
+ wake_up_interruptible(&r->pollq);
+
return 0;
}
@@ -106,11 +114,18 @@ static int iio_read_first_n_kfifo(struct iio_buffer *r,
int ret, copied;
struct iio_kfifo *kf = iio_to_kfifo(r);
- if (n < r->bytes_per_datum)
+ if (n < r->bytes_per_datum || r->bytes_per_datum == 0)
return -EINVAL;
- n = rounddown(n, r->bytes_per_datum);
ret = kfifo_to_user(&kf->kf, buf, n, &copied);
+ if (ret < 0)
+ return ret;
+
+ if (kfifo_is_empty(&kf->kf))
+ r->stufftoread = false;
+ /* verify it is still empty to avoid race */
+ if (!kfifo_is_empty(&kf->kf))
+ r->stufftoread = true;
return copied;
}
@@ -136,7 +151,7 @@ struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
iio_buffer_init(&kf->buffer);
kf->buffer.attrs = &iio_kfifo_attribute_group;
kf->buffer.access = &kfifo_access_funcs;
-
+ kf->buffer.length = 2;
return &kf->buffer;
}
EXPORT_SYMBOL(iio_kfifo_allocate);