V4L/DVB (12424): soc-camera: fix recursive locking in .buf_queue()

The .buf_queue() V4L2 driver method is called under
spinlock_irqsave(q->irqlock,...), don't take the lock again inside the
function.
Reported-by: Antonio Ospite <ospite@studenti.unina.it>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/mx1_camera.c

@@ -234,6 +234,7 @@ static int mx1_camera_setup_dma(struct mx1_camera_dev *pcdev)
 	return ret;
 }
 
+/* Called under spinlock_irqsave(&pcdev->lock, ...) */
 static void mx1_videobuf_queue(struct videobuf_queue *vq,
 						struct videobuf_buffer *vb)
 {
@@ -241,13 +242,10 @@ static void mx1_videobuf_queue(struct videobuf_queue *vq,
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
 	struct mx1_camera_dev *pcdev = ici->priv;
 	struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);
-	unsigned long flags;
 
 	dev_dbg(&icd->dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
 		vb, vb->baddr, vb->bsize);
 
-	spin_lock_irqsave(&pcdev->lock, flags);
-
 	list_add_tail(&vb->queue, &pcdev->capture);
 
 	vb->state = VIDEOBUF_ACTIVE;
@@ -264,8 +262,6 @@ static void mx1_videobuf_queue(struct videobuf_queue *vq,
 			__raw_writel(temp, pcdev->base + CSICR1);
 		}
 	}
-
-	spin_unlock_irqrestore(&pcdev->lock, flags);
 }
 
 static void mx1_videobuf_release(struct videobuf_queue *vq,

drivers/media/video/mx3_camera.c

@@ -332,7 +332,10 @@ static enum pixel_fmt fourcc_to_ipu_pix(__u32 fourcc)
 	}
 }
 
-/* Called with .vb_lock held */
+/*
+ * Called with .vb_lock mutex held and
+ * under spinlock_irqsave(&mx3_cam->lock, ...)
+ */
 static void mx3_videobuf_queue(struct videobuf_queue *vq,
 			       struct videobuf_buffer *vb)
 {
@@ -346,7 +349,8 @@ static void mx3_videobuf_queue(struct videobuf_queue *vq,
 	struct idmac_video_param *video = &ichan->params.video;
 	const struct soc_camera_data_format *data_fmt = icd->current_fmt;
 	dma_cookie_t cookie;
-	unsigned long flags;
+
+	BUG_ON(!irqs_disabled());
 
 	/* This is the configuration of one sg-element */
 	video->out_pixel_fmt	= fourcc_to_ipu_pix(data_fmt->fourcc);
@@ -359,8 +363,6 @@ static void mx3_videobuf_queue(struct videobuf_queue *vq,
 	memset((void *)vb->baddr, 0xaa, vb->bsize);
 #endif
 
-	spin_lock_irqsave(&mx3_cam->lock, flags);
-
 	list_add_tail(&vb->queue, &mx3_cam->capture);
 
 	if (!mx3_cam->active) {
@@ -370,24 +372,23 @@ static void mx3_videobuf_queue(struct videobuf_queue *vq,
 		vb->state = VIDEOBUF_QUEUED;
 	}
 
-	spin_unlock_irqrestore(&mx3_cam->lock, flags);
+	spin_unlock_irq(&mx3_cam->lock);
 
 	cookie = txd->tx_submit(txd);
 	dev_dbg(&icd->dev, "Submitted cookie %d DMA 0x%08x\n", cookie, sg_dma_address(&buf->sg));
+
+	spin_lock_irq(&mx3_cam->lock);
+
 	if (cookie >= 0)
 		return;
 
 	/* Submit error */
 	vb->state = VIDEOBUF_PREPARED;
 
-	spin_lock_irqsave(&mx3_cam->lock, flags);
-
 	list_del_init(&vb->queue);
 
 	if (mx3_cam->active == buf)
 		mx3_cam->active = NULL;
-
-	spin_unlock_irqrestore(&mx3_cam->lock, flags);
 }
 
 /* Called with .vb_lock held */

drivers/media/video/pxa_camera.c

@@ -612,6 +612,7 @@ static void pxa_camera_stop_capture(struct pxa_camera_dev *pcdev)
 	dev_dbg(pcdev->soc_host.dev, "%s\n", __func__);
 }
 
+/* Called under spinlock_irqsave(&pcdev->lock, ...) */
 static void pxa_videobuf_queue(struct videobuf_queue *vq,
 			       struct videobuf_buffer *vb)
 {
@@ -619,13 +620,10 @@ static void pxa_videobuf_queue(struct videobuf_queue *vq,
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
 	struct pxa_camera_dev *pcdev = ici->priv;
 	struct pxa_buffer *buf = container_of(vb, struct pxa_buffer, vb);
-	unsigned long flags;
 
 	dev_dbg(&icd->dev, "%s (vb=0x%p) 0x%08lx %d active=%p\n", __func__,
 		vb, vb->baddr, vb->bsize, pcdev->active);
 
-	spin_lock_irqsave(&pcdev->lock, flags);
-
 	list_add_tail(&vb->queue, &pcdev->capture);
 
 	vb->state = VIDEOBUF_ACTIVE;
@@ -633,8 +631,6 @@ static void pxa_videobuf_queue(struct videobuf_queue *vq,
 
 	if (!pcdev->active)
 		pxa_camera_start_capture(pcdev);
-
-	spin_unlock_irqrestore(&pcdev->lock, flags);
 }
 
 static void pxa_videobuf_release(struct videobuf_queue *vq,

drivers/media/video/sh_mobile_ceu_camera.c

@@ -282,27 +282,24 @@ out:
 	return ret;
 }
 
+/* Called under spinlock_irqsave(&pcdev->lock, ...) */
 static void sh_mobile_ceu_videobuf_queue(struct videobuf_queue *vq,
 					 struct videobuf_buffer *vb)
 {
 	struct soc_camera_device *icd = vq->priv_data;
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
 	struct sh_mobile_ceu_dev *pcdev = ici->priv;
-	unsigned long flags;
 
 	dev_dbg(&icd->dev, "%s (vb=0x%p) 0x%08lx %zd\n", __func__,
 		vb, vb->baddr, vb->bsize);
 
 	vb->state = VIDEOBUF_QUEUED;
-	spin_lock_irqsave(&pcdev->lock, flags);
 	list_add_tail(&vb->queue, &pcdev->capture);
 
 	if (!pcdev->active) {
 		pcdev->active = vb;
 		sh_mobile_ceu_capture(pcdev);
 	}
-
-	spin_unlock_irqrestore(&pcdev->lock, flags);
 }
 
 static void sh_mobile_ceu_videobuf_release(struct videobuf_queue *vq,