From 99cfdf5cc6dbe0bd748d810953874d4e08051a9f Mon Sep 17 00:00:00 2001 From: Pantelis Koukousoulas Date: Wed, 27 Dec 2006 23:08:55 -0300 Subject: [PATCH] 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 Signed-off-by: Mike Isely Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/pvrusb2/pvrusb2-context.c | 11 +++++++++++ drivers/media/video/pvrusb2/pvrusb2-context.h | 2 ++ 2 files changed, 13 insertions(+) diff --git a/drivers/media/video/pvrusb2/pvrusb2-context.c b/drivers/media/video/pvrusb2/pvrusb2-context.c index cf129746205d..69786cdaa859 100644 --- a/drivers/media/video/pvrusb2/pvrusb2-context.c +++ b/drivers/media/video/pvrusb2/pvrusb2-context.c @@ -188,6 +188,17 @@ void pvr2_channel_done(struct pvr2_channel *cp) } +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 6327fa1f7e4f..4d0f4ad64122 100644 --- a/drivers/media/video/pvrusb2/pvrusb2-context.h +++ b/drivers/media/video/pvrusb2/pvrusb2-context.h @@ -76,6 +76,8 @@ void pvr2_channel_init(struct pvr2_channel *,struct pvr2_context *); 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 *); -- 2.20.1