From: Hans Verkuil Date: Tue, 10 Jul 2007 17:58:33 +0000 (-0300) Subject: V4L/DVB (5842): ivtv: Add locking to ensure stream setup is atomic. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f885969196da6ae905162c0d1c5f0553de12cb40;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git 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: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/video/ivtv/ivtv-driver.c b/drivers/media/video/ivtv/ivtv-driver.c index 28a53c42020..ab7c3f6d353 100644 --- a/drivers/media/video/ivtv/ivtv-driver.c +++ b/drivers/media/video/ivtv/ivtv-driver.c @@ -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); diff --git a/drivers/media/video/ivtv/ivtv-driver.h b/drivers/media/video/ivtv/ivtv-driver.h index 48afd4270cb..65ebddab3fe 100644 --- a/drivers/media/video/ivtv/ivtv-driver.h +++ b/drivers/media/video/ivtv/ivtv-driver.h @@ -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; diff --git a/drivers/media/video/ivtv/ivtv-streams.c b/drivers/media/video/ivtv/ivtv-streams.c index 6af88ae9295..d538efaf61c 100644 --- a/drivers/media/video/ivtv/ivtv-streams.c +++ b/drivers/media/video/ivtv/ivtv-streams.c @@ -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; }