Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4abec468 authored by Ian Molton's avatar Ian Molton Committed by Mauro Carvalho Chehab
Browse files

[media] rcar_vin: helper function for streaming stop 



The code that tests that capture from a stream has stopped is
presently insufficient and the potential for a race condition
exists where frame capture may generate an interrupt between
requesting the capture process halt and freeing buffers.

This patch refactors code out of rcar_vin_videobuf_release() and
into rcar_vin_wait_stop_streaming(), and ensures there are calls
in places where we need to know that capturing has finished.

Signed-off-by: default avatarIan Molton <ian.molton@codethink.co.uk>
Signed-off-by: default avatarWilliam Towle <william.towle@codethink.co.uk>
Signed-off-by: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent 650b1815

drivers/media/platform/soc_camera/rcar_vin.c

+27 −14
Original line number Diff line number Diff line
@@ -804,6 +804,28 @@ static void rcar_vin_videobuf_queue(struct vb2_buffer *vb) 
	vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);

}



/*

 * Wait for capture to stop and all in-flight buffers to be finished with by

 * the video hardware. This must be called under &priv->lock

 *

 */

static void rcar_vin_wait_stop_streaming(struct rcar_vin_priv *priv)

{

	while (priv->state != STOPPED) {

		/* issue stop if running */

		if (priv->state == RUNNING)

			rcar_vin_request_capture_stop(priv);



		/* wait until capturing has been stopped */

		if (priv->state == STOPPING) {

			priv->request_to_stop = true;

			spin_unlock_irq(&priv->lock);

			wait_for_completion(&priv->capture_stop);

			spin_lock_irq(&priv->lock);

		}

	}

}



static void rcar_vin_videobuf_release(struct vb2_buffer *vb)

{

	struct soc_camera_device *icd = soc_camera_from_vb2q(vb->vb2_queue);
@@ -823,20 +845,8 @@ static void rcar_vin_videobuf_release(struct vb2_buffer *vb) 
	}



	if (buf_in_use) {

		while (priv->state != STOPPED) {

		rcar_vin_wait_stop_streaming(priv);



			/* issue stop if running */

			if (priv->state == RUNNING)

				rcar_vin_request_capture_stop(priv);



			/* wait until capturing has been stopped */

			if (priv->state == STOPPING) {

				priv->request_to_stop = true;

				spin_unlock_irq(&priv->lock);

				wait_for_completion(&priv->capture_stop);

				spin_lock_irq(&priv->lock);

			}

		}

		/*

		 * Capturing has now stopped. The buffer we have been asked

		 * to release could be any of the current buffers in use, so
@@ -870,8 +880,11 @@ static void rcar_vin_stop_streaming(struct vb2_queue *vq) 
	struct list_head *buf_head, *tmp;



	spin_lock_irq(&priv->lock);



	rcar_vin_wait_stop_streaming(priv);

	list_for_each_safe(buf_head, tmp, &priv->capture)

		list_del_init(buf_head);



	spin_unlock_irq(&priv->lock);

}