Staging: b3dfg: Drop NULL test on list_entry result
list_entry, which is an alias for container_of, cannot return NULL, as
there is no way to add a NULL value to a doubly linked list.
A simplified version of the semantic match that findds this problem is as
follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r@
expression x,E;
statement S1,S2;
position p,p1;
@@
*x = list_entry@p(...)
... when != x = E
*if@p1 (x == NULL) S1 else S2
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/b3dfg/b3dfg.c b/drivers/staging/b3dfg/b3dfg.c
index eec9c99..94c5d27 100644
--- a/drivers/staging/b3dfg/b3dfg.c
+++ b/drivers/staging/b3dfg/b3dfg.c
@@ -632,18 +632,15 @@
fgdev->cur_dma_frame_addr = 0;
buf = list_entry(fgdev->buffer_queue.next, struct b3dfg_buffer, list);
- if (buf) {
- dev_dbg(dev, "handle frame completion\n");
- if (fgdev->cur_dma_frame_idx == B3DFG_FRAMES_PER_BUFFER - 1) {
- /* last frame of that triplet completed */
- dev_dbg(dev, "triplet completed\n");
- buf->state = B3DFG_BUFFER_POPULATED;
- list_del_init(&buf->list);
- wake_up_interruptible(&fgdev->buffer_waitqueue);
- }
- } else {
- dev_err(dev, "got frame but no buffer!\n");
+ dev_dbg(dev, "handle frame completion\n");
+ if (fgdev->cur_dma_frame_idx == B3DFG_FRAMES_PER_BUFFER - 1) {
+
+ /* last frame of that triplet completed */
+ dev_dbg(dev, "triplet completed\n");
+ buf->state = B3DFG_BUFFER_POPULATED;
+ list_del_init(&buf->list);
+ wake_up_interruptible(&fgdev->buffer_waitqueue);
}
}
@@ -663,19 +660,15 @@
dev_dbg(dev, "program DMA transfer for next frame: %d\n", idx);
buf = list_entry(fgdev->buffer_queue.next, struct b3dfg_buffer, list);
- if (buf) {
- if (idx == fgdev->cur_dma_frame_idx + 2) {
- if (setup_frame_transfer(fgdev, buf, idx - 1))
- dev_err(dev, "unable to map DMA buffer\n");
- need_ack = 0;
- } else {
- dev_err(dev, "frame mismatch, got %d, expected %d\n",
- idx, fgdev->cur_dma_frame_idx + 2);
-
- /* FIXME: handle dropped triplets here */
- }
+ if (idx == fgdev->cur_dma_frame_idx + 2) {
+ if (setup_frame_transfer(fgdev, buf, idx - 1))
+ dev_err(dev, "unable to map DMA buffer\n");
+ need_ack = 0;
} else {
- dev_err(dev, "cannot setup DMA, no buffer\n");
+ dev_err(dev, "frame mismatch, got %d, expected %d\n",
+ idx, fgdev->cur_dma_frame_idx + 2);
+
+ /* FIXME: handle dropped triplets here */
}
return need_ack;