1 files changed, 16 insertions, 56 deletions

diff --git a/drivers/staging/iio/kfifo_buf.c b/drivers/staging/iio/kfifo_buf.c
index e8c234bb18f0..e1e9c06cde4a 100644
--- a/drivers/staging/iio/kfifo_buf.c
+++ b/drivers/staging/iio/kfifo_buf.c
@@ -11,9 +11,7 @@
 struct iio_kfifo {
 	struct iio_buffer buffer;
 	struct kfifo kf;
-	int use_count;
 	int update_needed;
-	struct mutex use_lock;
 };
 
 #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
@@ -33,54 +31,25 @@ static int iio_request_update_kfifo(struct iio_buffer *r)
 	int ret = 0;
 	struct iio_kfifo *buf = iio_to_kfifo(r);
 
-	mutex_lock(&buf->use_lock);
 	if (!buf->update_needed)
 		goto error_ret;
-	if (buf->use_count) {
-		ret = -EAGAIN;
-		goto error_ret;
-	}
 	kfifo_free(&buf->kf);
 	ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
 				   buf->buffer.length);
 error_ret:
-	mutex_unlock(&buf->use_lock);
 	return ret;
 }
 
-static void iio_mark_kfifo_in_use(struct iio_buffer *r)
-{
-	struct iio_kfifo *buf = iio_to_kfifo(r);
-	mutex_lock(&buf->use_lock);
-	buf->use_count++;
-	mutex_unlock(&buf->use_lock);
-}
-
-static void iio_unmark_kfifo_in_use(struct iio_buffer *r)
-{
-	struct iio_kfifo *buf = iio_to_kfifo(r);
-	mutex_lock(&buf->use_lock);
-	buf->use_count--;
-	mutex_unlock(&buf->use_lock);
-}
-
 static int iio_get_length_kfifo(struct iio_buffer *r)
 {
 	return r->length;
 }
 
-static inline void __iio_init_kfifo(struct iio_kfifo *kf)
-{
-	mutex_init(&kf->use_lock);
-}
-
 static IIO_BUFFER_ENABLE_ATTR;
-static IIO_BUFFER_BYTES_PER_DATUM_ATTR;
 static IIO_BUFFER_LENGTH_ATTR;
 
 static struct attribute *iio_kfifo_attributes[] = {
 	&dev_attr_length.attr,
-	&dev_attr_bytes_per_datum.attr,
 	&dev_attr_enable.attr,
 	NULL,
 };
@@ -98,9 +67,8 @@ struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
 	if (!kf)
 		return NULL;
 	kf->update_needed = true;
-	iio_buffer_init(&kf->buffer, indio_dev);
+	iio_buffer_init(&kf->buffer);
 	kf->buffer.attrs = &iio_kfifo_attribute_group;
-	__iio_init_kfifo(kf);
 
 	return &kf->buffer;
 }
@@ -111,20 +79,19 @@ static int iio_get_bytes_per_datum_kfifo(struct iio_buffer *r)
 	return r->bytes_per_datum;
 }
 
-static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
+static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
 {
-	if (r->bytes_per_datum != bpd) {
-		r->bytes_per_datum = bpd;
-		if (r->access->mark_param_change)
-			r->access->mark_param_change(r);
-	}
+	struct iio_kfifo *kf = iio_to_kfifo(r);
+	kf->update_needed = true;
 	return 0;
 }
 
-static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
+static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
 {
-	struct iio_kfifo *kf = iio_to_kfifo(r);
-	kf->update_needed = true;
+	if (r->bytes_per_datum != bpd) {
+		r->bytes_per_datum = bpd;
+		iio_mark_update_needed_kfifo(r);
+	}
 	return 0;
 }
 
@@ -132,8 +99,7 @@ static int iio_set_length_kfifo(struct iio_buffer *r, int length)
 {
 	if (r->length != length) {
 		r->length = length;
-		if (r->access->mark_param_change)
-			r->access->mark_param_change(r);
+		iio_mark_update_needed_kfifo(r);
 	}
 	return 0;
 }
@@ -150,16 +116,9 @@ static int iio_store_to_kfifo(struct iio_buffer *r,
 {
 	int ret;
 	struct iio_kfifo *kf = iio_to_kfifo(r);
-	u8 *datal = kmalloc(r->bytes_per_datum, GFP_KERNEL);
-	memcpy(datal, data, r->bytes_per_datum - sizeof(timestamp));
-	memcpy(datal + r->bytes_per_datum - sizeof(timestamp),
-		&timestamp, sizeof(timestamp));
 	ret = kfifo_in(&kf->kf, data, r->bytes_per_datum);
-	if (ret != r->bytes_per_datum) {
-		kfree(datal);
+	if (ret != r->bytes_per_datum)
 		return -EBUSY;
-	}
-	kfree(datal);
 	return 0;
 }
 
@@ -169,17 +128,18 @@ static int iio_read_first_n_kfifo(struct iio_buffer *r,
 	int ret, copied;
 	struct iio_kfifo *kf = iio_to_kfifo(r);
 
-	ret = kfifo_to_user(&kf->kf, buf, r->bytes_per_datum*n, &copied);
+	if (n < r->bytes_per_datum)
+		return -EINVAL;
+
+	n = rounddown(n, r->bytes_per_datum);
+	ret = kfifo_to_user(&kf->kf, buf, n, &copied);
 
 	return copied;
 }
 
 const struct iio_buffer_access_funcs kfifo_access_funcs = {
-	.mark_in_use = &iio_mark_kfifo_in_use,
-	.unmark_in_use = &iio_unmark_kfifo_in_use,
 	.store_to = &iio_store_to_kfifo,
 	.read_first_n = &iio_read_first_n_kfifo,
-	.mark_param_change = &iio_mark_update_needed_kfifo,
 	.request_update = &iio_request_update_kfifo,
 	.get_bytes_per_datum = &iio_get_bytes_per_datum_kfifo,
 	.set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,