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Commit e7c50688 authored by Guennadi Liakhovetski's avatar Guennadi Liakhovetski Committed by Mauro Carvalho Chehab
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V4L/DVB (7670): pxa-camera: handle FIFO overruns 



FIFO overruns are not seldom on PXA camera interface FIFOs. Handle them by
dropping the corrupted frame, waiting for the next start-of-frame, and
restarting capture.

Signed-off-by: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@infradead.org>
parent a5462e5b

drivers/media/video/pxa_camera.c

+39 −20
Original line number Diff line number Diff line
@@ -118,6 +118,7 @@ struct pxa_camera_dev { 
	unsigned int		irq;

	void __iomem		*base;



	int			channels;

	unsigned int		dma_chans[3];



	struct pxacamera_platform_data *pdata;
@@ -398,14 +399,10 @@ static void pxa_videobuf_queue(struct videobuf_queue *vq, 
	} else {

		struct pxa_cam_dma *buf_dma;

		struct pxa_cam_dma *act_dma;

		int channels = 1;

		int nents;

		int i;



		if (buf->fmt->fourcc == V4L2_PIX_FMT_YUV422P)

			channels = 3;



		for (i = 0; i < channels; i++) {

		for (i = 0; i < pcdev->channels; i++) {

			buf_dma = &buf->dmas[i];

			act_dma = &active->dmas[i];

			nents = buf_dma->sglen;
@@ -445,20 +442,6 @@ static void pxa_videobuf_queue(struct videobuf_queue *vq, 


			DCSR(pcdev->dma_chans[i]) = DCSR_RUN;

		}

#ifdef DEBUG

		if (CISR & (CISR_IFO_0 | CISR_IFO_1 | CISR_IFO_2)) {

			dev_warn(pcdev->dev, "FIFO overrun\n");

			for (i = 0; i < channels; i++)

				DDADR(pcdev->dma_chans[i]) =

					pcdev->active->dmas[i].sg_dma;



			CICR0 &= ~CICR0_ENB;

			CIFR |= CIFR_RESET_F;

			for (i = 0; i < channels; i++)

				DCSR(pcdev->dma_chans[i]) = DCSR_RUN;

			CICR0 |= CICR0_ENB;

		}

#endif

	}



	spin_unlock_irqrestore(&pcdev->lock, flags);
@@ -522,7 +505,7 @@ static void pxa_camera_dma_irq(int channel, struct pxa_camera_dev *pcdev, 
{

	struct pxa_buffer *buf;

	unsigned long flags;

	unsigned int status;

	u32 status, camera_status, overrun;

	struct videobuf_buffer *vb;



	spin_lock_irqsave(&pcdev->lock, flags);
@@ -546,6 +529,25 @@ static void pxa_camera_dma_irq(int channel, struct pxa_camera_dev *pcdev, 
		goto out;

	}



	camera_status = CISR;

	overrun = CISR_IFO_0;

	if (pcdev->channels == 3)

		overrun |= CISR_IFO_1 | CISR_IFO_2;

	if (camera_status & overrun) {

		dev_dbg(pcdev->dev, "FIFO overrun! CISR: %x\n", camera_status);

		/* Stop the Capture Interface */

		CICR0 &= ~CICR0_ENB;

		/* Stop DMA */

		DCSR(channel) = 0;

		/* Reset the FIFOs */

		CIFR |= CIFR_RESET_F;

		/* Enable End-Of-Frame Interrupt */

		CICR0 &= ~CICR0_EOFM;

		/* Restart the Capture Interface */

		CICR0 |= CICR0_ENB;

		goto out;

	}



	vb = &pcdev->active->vb;

	buf = container_of(vb, struct pxa_buffer, vb);

	WARN_ON(buf->inwork || list_empty(&vb->queue));
@@ -670,7 +672,21 @@ static irqreturn_t pxa_camera_irq(int irq, void *data) 


	dev_dbg(pcdev->dev, "Camera interrupt status 0x%x\n", status);



	if (!status)

		return IRQ_NONE;



	CISR = status;



	if (status & CISR_EOF) {

		int i;

		for (i = 0; i < pcdev->channels; i++) {

			DDADR(pcdev->dma_chans[i]) =

				pcdev->active->dmas[i].sg_dma;

			DCSR(pcdev->dma_chans[i]) = DCSR_RUN;

		}

		CICR0 |= CICR0_EOFM;

	}



	return IRQ_HANDLED;

}
@@ -785,6 +801,8 @@ static int pxa_camera_set_bus_param(struct soc_camera_device *icd, __u32 pixfmt) 
	if (!common_flags)

		return -EINVAL;



	pcdev->channels = 1;



	/* Make choises, based on platform preferences */

	if ((common_flags & SOCAM_HSYNC_ACTIVE_HIGH) &&

	    (common_flags & SOCAM_HSYNC_ACTIVE_LOW)) {
@@ -855,6 +873,7 @@ static int pxa_camera_set_bus_param(struct soc_camera_device *icd, __u32 pixfmt) 


	switch (pixfmt) {

	case V4L2_PIX_FMT_YUV422P:

		pcdev->channels = 3;

		cicr1 |= CICR1_YCBCR_F;

	case V4L2_PIX_FMT_YUYV:

		cicr1 |= CICR1_COLOR_SP_VAL(2);