v4l-helpers: Don't close the fd in {}_s_fd

v4l_queue_export_bufs uses the v4l_fd type when calling EXPBUF ioctl. However, this doesn't work on mem2mem where there are one capture queue and one output queue associated to the device.

The current code calls v4l_queue_export_bufs with the wrong type, failing as:

fail: v4l2-test-buffers.cpp(544): q_.export_bufs(node) test VIDIOC_EXPBUF: FAIL

Fix this by using the queue type instead.

Signed-off-by Ezequiel Garcia <[email protected]>

---
 utils/common/v4l-helpers.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

utils/common/v4l-helpers.h +1 -1

index 83d8d7d9c073..d6866f04e23a 100644
@@ -1633,7 +1633,7 @@ static inline int v4l_queue_export_bufs(struct v4l_fd *f, struct v4l_queue *q,
 	unsigned b, p;
 	int ret = 0;
 
-	expbuf.type = exp_type ? : f->type;
+	expbuf.type = exp_type ? : q->type;
 	expbuf.flags = O_RDWR;
 	memset(expbuf.reserved, 0, sizeof(expbuf.reserved));
 	for (b = 0; b < v4l_queue_g_buffers(q); b++) {

When creating a second node via copy or assignment:

node2 = node

The node being assigned to, i.e. node2, obtains the fd. This causes a later call to node2.media_open to close() the fd, thus unintendenly closing the original node fd, via the call path (e.g. for media devices):

node2.media_open

     v4l_media_open
        v4l_media_s_fd

Similar call paths apply for other device types. Fix this by removing the close in xxx_s_fd.

Signed-off-by Ezequiel Garcia <[email protected]>

---
 utils/common/v4l-helpers.h | 9 ---------
 1 file changed, 9 deletions(-)

utils/common/v4l-helpers.h +0 -9

index c37b72712126..83d8d7d9c073 100644
@@ -444,9 +444,6 @@ static inline int v4l_s_fd(struct v4l_fd *f, int fd, const char *devname, bool d
 	struct v4l2_queryctrl qc;
 	struct v4l2_selection sel;
 
-	if (f->fd >= 0)
-		f->close(f);
-
 	f->fd = fd;
 	f->direct = direct;
 	if (fd < 0)

@@ -492,9 +489,6 @@ static inline int v4l_open(struct v4l_fd *f, const char *devname, bool non_block
 
 static inline int v4l_subdev_s_fd(struct v4l_fd *f, int fd, const char *devname)
 {
-	if (f->fd >= 0)
-		f->close(f);
-
 	f->fd = fd;
 	f->direct = false;
 	if (fd < 0)

@@ -525,9 +519,6 @@ static inline int v4l_subdev_open(struct v4l_fd *f, const char *devname, bool no
 
 static inline int v4l_media_s_fd(struct v4l_fd *f, int fd, const char *devname)
 {
-	if (f->fd >= 0)
-		f->close(f);
-
 	f->fd = fd;
 	f->direct = false;
 	if (fd < 0)

Quoted 13 lines · Ezequiel Garcia

When creating a second node via copy or assignment:

node2 = node

The node being assigned to, i.e. node2, obtains the fd. This causes a later call to node2.media_open to close() the fd, thus unintendenly closing the original node fd, via the call path (e.g. for media devices):

node2.media_open

     v4l_media_open
        v4l_media_s_fd

Quoted 2 lines

Similar call paths apply for other device types. Fix this by removing the close in xxx_s_fd.

I fixed this in a different way by overloading the assignment operator
and calling dup(fd). That solves this as well.

Quoted 13 lines · Ezequiel Garcia

When creating a second node via copy or assignment:

node2 = node

The node being assigned to, i.e. node2, obtains the fd. This causes a later call to node2.media_open to close() the fd, thus unintendenly closing the original node fd, via the call path (e.g. for media devices):

node2.media_open

     v4l_media_open
        v4l_media_s_fd

Quoted 2 lines

Similar call paths apply for other device types. Fix this by removing the close in xxx_s_fd.

I fixed this in a different way by overloading the assignment operator
and calling dup(fd). That solves this as well.