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 <[email protected]> Signed-off-by: Guennadi Liakhovetski <[email protected]> --- Subject: Re: [BUG] pxa_camera: possible recursive locking detected On Tue, 4 Aug 2009, Antonio Ospite wrote: > Hi, > > verified to be present in linux-2.6.31-rc5, here's some info dumped > from RAM, since the machine hangs, sorry if it is not complete but I > couldn't get anything better for now, nothing is printed on > the screen. You're right, thanks for the report. Does the patch below fix the problem? It only gets a bit tricky in mx3_camera.c, will have to test. diff --git a/drivers/media/video/mx1_camera.c b/drivers/media/video/mx1_camera.c index 9632cb1..3e95c6d 100644 --- a/drivers/media/video/mx1_camera.c +++ b/drivers/media/video/mx1_camera.c @@ -235,6 +235,7 @@ 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) { @@ -247,8 +248,6 @@ static void mx1_videobuf_queue(struct videobuf_queue *vq, dev_dbg(icd->dev.parent, "%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; @@ -265,8 +264,6 @@ 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, diff --git a/drivers/media/video/mx3_camera.c b/drivers/media/video/mx3_camera.c index 6572ce7..1c70165 100644 --- a/drivers/media/video/mx3_camera.c +++ b/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) { @@ -348,6 +351,8 @@ static void mx3_videobuf_queue(struct videobuf_queue *vq, 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); video->out_width = icd->user_width; @@ -359,8 +364,6 @@ 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) { @@ -370,7 +373,7 @@ 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.parent, "Submitted cookie %d DMA 0x%08x\n", @@ -381,14 +384,12 @@ static void mx3_videobuf_queue(struct videobuf_queue *vq, /* Submit error */ vb->state = VIDEOBUF_PREPARED; - spin_lock_irqsave(&mx3_cam->lock, flags); + spin_lock_irq(&mx3_cam->lock); 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 */ diff --git a/drivers/media/video/pxa_camera.c b/drivers/media/video/pxa_camera.c index 7c86ef9..77be871 100644 --- a/drivers/media/video/pxa_camera.c +++ b/drivers/media/video/pxa_camera.c @@ -617,6 +617,7 @@ static void pxa_camera_stop_capture(struct pxa_camera_dev *pcdev) dev_dbg(pcdev->soc_host.v4l2_dev.dev, "%s\n", __func__); } +/* Called under spinlock_irqsave(&pcdev->lock, ...) */ static void pxa_videobuf_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb) { @@ -629,8 +630,6 @@ static void pxa_videobuf_queue(struct videobuf_queue *vq, dev_dbg(icd->dev.parent, "%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; @@ -638,8 +637,6 @@ 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, diff --git a/drivers/media/video/sh_mobile_ceu_camera.c b/drivers/media/video/sh_mobile_ceu_camera.c index 0aacb31..ce808a1 100644 --- a/drivers/media/video/sh_mobile_ceu_camera.c +++ b/drivers/media/video/sh_mobile_ceu_camera.c @@ -304,6 +304,7 @@ out: return ret; } +/* Called under spinlock_irqsave(&pcdev->lock, ...) */ static void sh_mobile_ceu_videobuf_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb) { @@ -315,7 +316,6 @@ static void sh_mobile_ceu_videobuf_queue(struct videobuf_queue *vq, dev_dbg(icd->dev.parent, "%s (vb=0x%p) 0x%08lx %zd\n", __func__, vb, vb->baddr, vb->bsize); - spin_lock_irqsave(&pcdev->lock, flags); vb->state = VIDEOBUF_QUEUED; list_add_tail(&vb->queue, &pcdev->capture); @@ -323,8 +323,6 @@ static void sh_mobile_ceu_videobuf_queue(struct videobuf_queue *vq, 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, -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
