V4L/DVB (5038): Pvrusb2: Implement stream claim checking function
Add (and expose) a new function, pvr2_channel_check_stream_no_lock(), in
pvrusb2-context.c. This is hopefully the last V4L2 interface related patch
to change anything outside pvrusb2-v4l2.c.
We need this to implement the open() for the radio device. The reason is
that within the *enter_context() section of open() we need to ensure nobody
is streaming and if we cannot, we should cleanup after ourselves and return
-EBUSY. We cannot just use claim_stream() because:
1) That would cause a deadlock trying to re-acquire the context lock
2) We only need to ensure that nobody is streaming. We don't need to
actually acquire the stream.
Again, this is a kinda ugly patch. Feel free to improve.
Signed-off-by: Pantelis Koukousoulas <pakt223@freemail.gr>
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/pvrusb2/pvrusb2-context.c b/drivers/media/video/pvrusb2/pvrusb2-context.c
index cf12974..69786cda 100644
--- a/drivers/media/video/pvrusb2/pvrusb2-context.c
+++ b/drivers/media/video/pvrusb2/pvrusb2-context.c
@@ -188,6 +188,17 @@
}
+int pvr2_channel_check_stream_no_lock(struct pvr2_channel *cp,
+ struct pvr2_context_stream *sp)
+{
+ if (sp == cp->stream) return 0;
+ if (sp->user) {
+ return -EBUSY;
+ }
+ return 0;
+}
+
+
int pvr2_channel_claim_stream(struct pvr2_channel *cp,
struct pvr2_context_stream *sp)
{
diff --git a/drivers/media/video/pvrusb2/pvrusb2-context.h b/drivers/media/video/pvrusb2/pvrusb2-context.h
index 6327fa1..4d0f4ad 100644
--- a/drivers/media/video/pvrusb2/pvrusb2-context.h
+++ b/drivers/media/video/pvrusb2/pvrusb2-context.h
@@ -76,6 +76,8 @@
void pvr2_channel_done(struct pvr2_channel *);
int pvr2_channel_claim_stream(struct pvr2_channel *,
struct pvr2_context_stream *);
+int pvr2_channel_check_stream_no_lock(struct pvr2_channel *,
+ struct pvr2_context_stream *);
struct pvr2_ioread *pvr2_channel_create_mpeg_stream(
struct pvr2_context_stream *);