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Commit 03878bb4 authored by Sylwester Nawrocki's avatar Sylwester Nawrocki Committed by Mauro Carvalho Chehab
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[media] s5p-fimc: fimc-lite: Prevent deadlock at STREAMON/OFF ioctls 



This patch fixes regression introduced in commit 6319d6a002beb26631
'[media] fimc-lite: Add ISP FIFO output support'.
In case of a configuration where video is captured at the video node
exposed by the FIMC-LITE driver there is a following video pipeline:
sensor -> MIPI-CSIS.n -> FIMC-LITE.n subdev -> FIMC-LITE.n video node
In this situation s_stream() handler of the FIMC-LITE.n is called
back from within VIDIOC_STREAMON/OFF ioctl of the FIMC-LITE.n video
node, through vb2_stream_on/off(), start/stop_streaming and
fimc_pipeline_call(set_stream). The fimc->lock mutex is already held
then, before invoking vidioc_streamon/off. So it must not be taken
again in the s_stream() callback in this case, to avoid a deadlock.
This patch makes fimc->out_path atomic_t so the mutex don't need
to be taken in the FIMC-LITE subdev s_stream() callback in the DMA
output case.

Signed-off-by: default avatarSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: default avatarKyugmin Park <kyungmin.park@samsung.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 81b9f702

drivers/media/platform/s5p-fimc/fimc-lite-reg.c

+1 −1
Original line number Diff line number Diff line
@@ -65,7 +65,7 @@ void flite_hw_set_interrupt_mask(struct fimc_lite *dev) 
	u32 cfg, intsrc;



	/* Select interrupts to be enabled for each output mode */

	if (dev->out_path == FIMC_IO_DMA) {

	if (atomic_read(&dev->out_path) == FIMC_IO_DMA) {

		intsrc = FLITE_REG_CIGCTRL_IRQ_OVFEN |

			 FLITE_REG_CIGCTRL_IRQ_LASTEN |

			 FLITE_REG_CIGCTRL_IRQ_STARTEN;

drivers/media/platform/s5p-fimc/fimc-lite.c

+19 −16
Original line number Diff line number Diff line
@@ -260,7 +260,7 @@ static irqreturn_t flite_irq_handler(int irq, void *priv) 
		wake_up(&fimc->irq_queue);

	}



	if (fimc->out_path != FIMC_IO_DMA)

	if (atomic_read(&fimc->out_path) != FIMC_IO_DMA)

		goto done;



	if ((intsrc & FLITE_REG_CISTATUS_IRQ_SRC_FRMSTART) &&
@@ -465,7 +465,7 @@ static int fimc_lite_open(struct file *file) 
	mutex_lock(&me->parent->graph_mutex);



	mutex_lock(&fimc->lock);

	if (fimc->out_path != FIMC_IO_DMA) {

	if (atomic_read(&fimc->out_path) != FIMC_IO_DMA) {

		ret = -EBUSY;

		goto done;

	}
@@ -479,7 +479,8 @@ static int fimc_lite_open(struct file *file) 
	if (ret < 0)

		goto done;



	if (++fimc->ref_count == 1 && fimc->out_path == FIMC_IO_DMA) {

	if (++fimc->ref_count == 1 &&

	    atomic_read(&fimc->out_path) == FIMC_IO_DMA) {

		ret = fimc_pipeline_call(fimc, open, &fimc->pipeline,

					 &fimc->vfd.entity, true);

		if (ret < 0) {
@@ -504,7 +505,8 @@ static int fimc_lite_close(struct file *file) 


	mutex_lock(&fimc->lock);



	if (--fimc->ref_count == 0 && fimc->out_path == FIMC_IO_DMA) {

	if (--fimc->ref_count == 0 &&

	    atomic_read(&fimc->out_path) == FIMC_IO_DMA) {

		clear_bit(ST_FLITE_IN_USE, &fimc->state);

		fimc_lite_stop_capture(fimc, false);

		fimc_pipeline_call(fimc, close, &fimc->pipeline);
@@ -1034,18 +1036,18 @@ static int fimc_lite_link_setup(struct media_entity *entity, 


	case FLITE_SD_PAD_SOURCE_DMA:

		if (!(flags & MEDIA_LNK_FL_ENABLED))

			fimc->out_path = FIMC_IO_NONE;

			atomic_set(&fimc->out_path, FIMC_IO_NONE);

		else if (remote_ent_type == MEDIA_ENT_T_DEVNODE)

			fimc->out_path = FIMC_IO_DMA;

			atomic_set(&fimc->out_path, FIMC_IO_DMA);

		else

			ret = -EINVAL;

		break;



	case FLITE_SD_PAD_SOURCE_ISP:

		if (!(flags & MEDIA_LNK_FL_ENABLED))

			fimc->out_path = FIMC_IO_NONE;

			atomic_set(&fimc->out_path, FIMC_IO_NONE);

		else if (remote_ent_type == MEDIA_ENT_T_V4L2_SUBDEV)

			fimc->out_path = FIMC_IO_ISP;

			atomic_set(&fimc->out_path, FIMC_IO_ISP);

		else

			ret = -EINVAL;

		break;
@@ -1054,6 +1056,7 @@ static int fimc_lite_link_setup(struct media_entity *entity, 
		v4l2_err(sd, "Invalid pad index\n");

		ret = -EINVAL;

	}

	mb();



	mutex_unlock(&fimc->lock);

	return ret;
@@ -1123,8 +1126,10 @@ static int fimc_lite_subdev_set_fmt(struct v4l2_subdev *sd, 
	mf->colorspace = V4L2_COLORSPACE_JPEG;

	mutex_lock(&fimc->lock);



	if ((fimc->out_path == FIMC_IO_ISP && sd->entity.stream_count > 0) ||

	    (fimc->out_path == FIMC_IO_DMA && vb2_is_busy(&fimc->vb_queue))) {

	if ((atomic_read(&fimc->out_path) == FIMC_IO_ISP &&

	    sd->entity.stream_count > 0) ||

	    (atomic_read(&fimc->out_path) == FIMC_IO_DMA &&

	    vb2_is_busy(&fimc->vb_queue))) {

		mutex_unlock(&fimc->lock);

		return -EBUSY;

	}
@@ -1247,12 +1252,10 @@ static int fimc_lite_subdev_s_stream(struct v4l2_subdev *sd, int on) 
	 */

	fimc->sensor = __find_remote_sensor(&sd->entity);



	mutex_lock(&fimc->lock);

	if (fimc->out_path != FIMC_IO_ISP) {

		mutex_unlock(&fimc->lock);

	if (atomic_read(&fimc->out_path) != FIMC_IO_ISP)

		return -ENOIOCTLCMD;

	}



	mutex_lock(&fimc->lock);

	if (on) {

		flite_hw_reset(fimc);

		ret = fimc_lite_hw_init(fimc, true);
@@ -1298,7 +1301,7 @@ static int fimc_lite_subdev_registered(struct v4l2_subdev *sd) 
	memset(vfd, 0, sizeof(*vfd));



	fimc->fmt = &fimc_lite_formats[0];

	fimc->out_path = FIMC_IO_DMA;

	atomic_set(&fimc->out_path, FIMC_IO_DMA);



	snprintf(vfd->name, sizeof(vfd->name), "fimc-lite.%d.capture",

		 fimc->index);
@@ -1589,7 +1592,7 @@ static int fimc_lite_resume(struct device *dev) 
	INIT_LIST_HEAD(&fimc->active_buf_q);

	fimc_pipeline_call(fimc, open, &fimc->pipeline,

			   &fimc->vfd.entity, false);

	fimc_lite_hw_init(fimc, fimc->out_path == FIMC_IO_ISP);

	fimc_lite_hw_init(fimc, atomic_read(&fimc->out_path) == FIMC_IO_ISP);

	clear_bit(ST_FLITE_SUSPENDED, &fimc->state);



	for (i = 0; i < fimc->reqbufs_count; i++) {

drivers/media/platform/s5p-fimc/fimc-lite.h

+1 −1
Original line number Diff line number Diff line
@@ -159,7 +159,7 @@ struct fimc_lite { 
	unsigned long		payload[FLITE_MAX_PLANES];

	struct flite_frame	inp_frame;

	struct flite_frame	out_frame;

	enum fimc_datapath	out_path;

	atomic_t		out_path;

	unsigned int		source_subdev_grp_id;



	unsigned long		state;