media: ivtv: don't call s_stream(0) if not streaming

Recently a WARN_ON was added in v4l2-subdev.c to warn if s_stream was
called unnecessarily. The ivtv driver hits this once when it is loaded for
the first time. Add a bool to avoid this warning.

[hverkuil: added a comment for the sd_video_is_streaming field]

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/media/pci/ivtv/ivtv-driver.h b/drivers/media/pci/ivtv/ivtv-driver.h
index ce3a7ca..a6ffa99 100644 (file)
--- a/drivers/media/pci/ivtv/ivtv-driver.h
+++ b/drivers/media/pci/ivtv/ivtv-driver.h
@@ -619,6 +619,7 @@ struct ivtv {
        u32 hw_flags;                   /* hardware description of the board */
        v4l2_std_id tuner_std;          /* the norm of the card's tuner (fixed) */
        struct v4l2_subdev *sd_video;   /* controlling video decoder subdev */
+       bool sd_video_is_streaming;     /* is video already streaming? */
        struct v4l2_subdev *sd_audio;   /* controlling audio subdev */
        struct v4l2_subdev *sd_muxer;   /* controlling audio muxer subdev */
        resource_size_t base_addr;      /* PCI resource base address */

diff --git a/drivers/media/pci/ivtv/ivtv-streams.c b/drivers/media/pci/ivtv/ivtv-streams.c
index 13d7d55..af9e623 100644 (file)
--- a/drivers/media/pci/ivtv/ivtv-streams.c
+++ b/drivers/media/pci/ivtv/ivtv-streams.c
@@ -623,10 +623,12 @@ int ivtv_start_v4l2_encode_stream(struct ivtv_stream *s)
                /* Avoid tinny audio problem - ensure audio clocks are going */
                v4l2_subdev_call(itv->sd_audio, audio, s_stream, 1);
                /* Avoid unpredictable PCI bus hang - disable video clocks */
-               v4l2_subdev_call(itv->sd_video, video, s_stream, 0);
+               if (itv->sd_video_is_streaming)
+                       v4l2_subdev_call(itv->sd_video, video, s_stream, 0);
                ivtv_msleep_timeout(300, 0);
                ivtv_vapi(itv, CX2341X_ENC_INITIALIZE_INPUT, 0);
                v4l2_subdev_call(itv->sd_video, video, s_stream, 1);
+               itv->sd_video_is_streaming = true;
        }
 
        /* begin_capture */