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Commit f8859691 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
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V4L/DVB (5842): ivtv: Add locking to ensure stream setup is atomic. 



Starting an MPEG and VBI capture simultaneously caused errors in
the VBI setup: this setup was done twice when it should be done
only for the first stream that is opened.
Added a mutex to prevent this from happening.

Signed-off-by: default avatarHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@infradead.org>
parent 0901973f

drivers/media/video/ivtv/ivtv-driver.c

+1 −0
Original line number Diff line number Diff line
@@ -623,6 +623,7 @@ static int __devinit ivtv_init_struct1(struct ivtv *itv) 
	itv->enc_mbox.max_mbox = 2; /* the encoder has 3 mailboxes (0-2) */

	itv->dec_mbox.max_mbox = 1; /* the decoder has 2 mailboxes (0-1) */



	mutex_init(&itv->serialize_lock);

	mutex_init(&itv->i2c_bus_lock);

	mutex_init(&itv->udma.lock);

drivers/media/video/ivtv/ivtv-driver.h

+1 −0
Original line number Diff line number Diff line
@@ -722,6 +722,7 @@ struct ivtv { 
	int search_pack_header;



	spinlock_t dma_reg_lock; /* lock access to DMA engine registers */

	struct mutex serialize_lock;  /* lock used to serialize starting streams */



	/* User based DMA for OSD */

	struct ivtv_user_dma udma;

drivers/media/video/ivtv/ivtv-streams.c

+19 −11
Original line number Diff line number Diff line
@@ -446,6 +446,9 @@ int ivtv_start_v4l2_encode_stream(struct ivtv_stream *s) 
	if (s->v4l2dev == NULL)

		return -EINVAL;



	/* Big serialization lock to ensure no two streams are started

	   simultaneously: that can give all sorts of weird results. */

	mutex_lock(&itv->serialize_lock);

	IVTV_DEBUG_INFO("Start encoder stream %s\n", s->name);



	switch (s->type) {
@@ -487,6 +490,7 @@ int ivtv_start_v4l2_encode_stream(struct ivtv_stream *s) 
			0, sizeof(itv->vbi.sliced_mpeg_size));

		break;

	default:

		mutex_unlock(&itv->serialize_lock);

		return -EINVAL;

	}

	s->subtype = subtype;
@@ -568,6 +572,7 @@ int ivtv_start_v4l2_encode_stream(struct ivtv_stream *s) 
	if (ivtv_vapi(itv, CX2341X_ENC_START_CAPTURE, 2, captype, subtype))

	{

		IVTV_DEBUG_WARN( "Error starting capture!\n");

		mutex_unlock(&itv->serialize_lock);

		return -EINVAL;

	}
@@ -583,6 +588,7 @@ int ivtv_start_v4l2_encode_stream(struct ivtv_stream *s) 


	/* you're live! sit back and await interrupts :) */

	atomic_inc(&itv->capturing);

	mutex_unlock(&itv->serialize_lock);

	return 0;

}
@@ -762,17 +768,6 @@ int ivtv_stop_v4l2_encode_stream(struct ivtv_stream *s, int gop_end) 
	/* when: 0 =  end of GOP  1 = NOW!, type: 0 = mpeg, subtype: 3 = video+audio */

	ivtv_vapi(itv, CX2341X_ENC_STOP_CAPTURE, 3, stopmode, cap_type, s->subtype);



	/* only run these if we're shutting down the last cap */

	if (atomic_read(&itv->capturing) - 1 == 0) {

		/* event notification (off) */

		if (test_and_clear_bit(IVTV_F_I_DIG_RST, &itv->i_flags)) {

			/* type: 0 = refresh */

			/* on/off: 0 = off, intr: 0x10000000, mbox_id: -1: none */

			ivtv_vapi(itv, CX2341X_ENC_SET_EVENT_NOTIFICATION, 4, 0, 0, IVTV_IRQ_ENC_VIM_RST, -1);

			ivtv_set_irq_mask(itv, IVTV_IRQ_ENC_VIM_RST);

		}

	}



	then = jiffies;



	if (!test_bit(IVTV_F_S_PASSTHROUGH, &s->s_flags)) {
@@ -840,17 +835,30 @@ int ivtv_stop_v4l2_encode_stream(struct ivtv_stream *s, int gop_end) 
	/* Clear capture and no-read bits */

	clear_bit(IVTV_F_S_STREAMING, &s->s_flags);



	/* ensure these global cleanup actions are done only once */

	mutex_lock(&itv->serialize_lock);



	if (s->type == IVTV_ENC_STREAM_TYPE_VBI)

		ivtv_set_irq_mask(itv, IVTV_IRQ_ENC_VBI_CAP);



	if (atomic_read(&itv->capturing) > 0) {

		mutex_unlock(&itv->serialize_lock);

		return 0;

	}



	/* Set the following Interrupt mask bits for capture */

	ivtv_set_irq_mask(itv, IVTV_IRQ_MASK_CAPTURE);



	/* event notification (off) */

	if (test_and_clear_bit(IVTV_F_I_DIG_RST, &itv->i_flags)) {

		/* type: 0 = refresh */

		/* on/off: 0 = off, intr: 0x10000000, mbox_id: -1: none */

		ivtv_vapi(itv, CX2341X_ENC_SET_EVENT_NOTIFICATION, 4, 0, 0, IVTV_IRQ_ENC_VIM_RST, -1);

		ivtv_set_irq_mask(itv, IVTV_IRQ_ENC_VIM_RST);

	}



	wake_up(&s->waitq);

	mutex_unlock(&itv->serialize_lock);



	return 0;

}