From c0e9e6ba3488d6680600d6cad7fea5252c6f1dae Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Mon, 5 Dec 2011 22:18:26 +0000 Subject: [PATCH] staging:iio:ring_sw don't provide read last function. No longer needed as we don't have drivers providing sysfs access to buffered data. Signed-off-by: Jonathan Cameron Acked-by: Lars-Peter Clausen Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/ring_sw.c | 33 --------------------------------- 1 file changed, 33 deletions(-) diff --git a/drivers/staging/iio/ring_sw.c b/drivers/staging/iio/ring_sw.c index 98fe819..37d26e6 100644 --- a/drivers/staging/iio/ring_sw.c +++ b/drivers/staging/iio/ring_sw.c @@ -23,7 +23,6 @@ * @data: the ring buffer memory * @read_p: read pointer (oldest available) * @write_p: write pointer - * @last_written_p: read pointer (newest available) * @half_p: half buffer length behind write_p (event generation) * @use_count: reference count to prevent resizing when in use * @update_needed: flag to indicated change in size requested @@ -37,7 +36,6 @@ struct iio_sw_ring_buffer { unsigned char *data; unsigned char *read_p; unsigned char *write_p; - unsigned char *last_written_p; /* used to act as a point at which to signal an event */ unsigned char *half_p; int use_count; @@ -56,7 +54,6 @@ static inline int __iio_allocate_sw_ring_buffer(struct iio_sw_ring_buffer *ring, ring->data = kmalloc(length*ring->buf.bytes_per_datum, GFP_ATOMIC); ring->read_p = NULL; ring->write_p = NULL; - ring->last_written_p = NULL; ring->half_p = NULL; return ring->data ? 0 : -ENOMEM; } @@ -115,7 +112,6 @@ static int iio_store_to_sw_ring(struct iio_sw_ring_buffer *ring, * Always valid as either points to latest or second latest value. * Before this runs it is null and read attempts fail with -EAGAIN. */ - ring->last_written_p = ring->write_p; barrier(); /* temp_ptr used to ensure we never have an invalid pointer * it may be slightly lagging, but never invalid @@ -305,34 +301,6 @@ static int iio_store_to_sw_rb(struct iio_buffer *r, return iio_store_to_sw_ring(ring, data, timestamp); } -static int iio_read_last_from_sw_ring(struct iio_sw_ring_buffer *ring, - unsigned char *data) -{ - unsigned char *last_written_p_copy; - - iio_mark_sw_rb_in_use(&ring->buf); -again: - barrier(); - last_written_p_copy = ring->last_written_p; - barrier(); /*unnessecary? */ - /* Check there is anything here */ - if (last_written_p_copy == NULL) - return -EAGAIN; - memcpy(data, last_written_p_copy, ring->buf.bytes_per_datum); - - if (unlikely(ring->last_written_p != last_written_p_copy)) - goto again; - - iio_unmark_sw_rb_in_use(&ring->buf); - return 0; -} - -static int iio_read_last_from_sw_rb(struct iio_buffer *r, - unsigned char *data) -{ - return iio_read_last_from_sw_ring(iio_to_sw_ring(r), data); -} - static int iio_request_update_sw_rb(struct iio_buffer *r) { int ret = 0; @@ -435,7 +403,6 @@ const struct iio_buffer_access_funcs ring_sw_access_funcs = { .mark_in_use = &iio_mark_sw_rb_in_use, .unmark_in_use = &iio_unmark_sw_rb_in_use, .store_to = &iio_store_to_sw_rb, - .read_last = &iio_read_last_from_sw_rb, .read_first_n = &iio_read_first_n_sw_rb, .mark_param_change = &iio_mark_update_needed_sw_rb, .request_update = &iio_request_update_sw_rb, -- 2.7.4