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Commit fa3e686a authored by Pavel Pisa's avatar Pavel Pisa Committed by Russell King
Browse files

[ARM] 3601/1: i.MX/MX1 DMA error handling for signaled channels only 



Patch from Pavel Pisa

There has been bug, that dma_err_handler() touches even
channels not signaling error condition.

Problem noticed by Andrea Paterniani.

Signed-off-by: default avatarPavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent e22b04fb

arch/arm/mach-imx/dma.c

+39 −26
Original line number Diff line number Diff line
@@ -15,6 +15,9 @@ 
 *             Changed to support scatter gather DMA

 *             by taking Russell's code from RiscPC

 *

 *  2006-05-31 Pavel Pisa <pisa@cmp.felk.cvut.cz>

 *             Corrected error handling code.

 *

 */



#undef DEBUG
@@ -277,7 +280,7 @@ imx_dma_setup_sg(imx_dmach_t dma_ch, 
int

imx_dma_setup_handlers(imx_dmach_t dma_ch,

		       void (*irq_handler) (int, void *, struct pt_regs *),

		       void (*err_handler) (int, void *, struct pt_regs *),

		       void (*err_handler) (int, void *, struct pt_regs *, int),

		       void *data)

{

	struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch];
@@ -463,43 +466,53 @@ static irqreturn_t dma_err_handler(int irq, void *dev_id, struct pt_regs *regs) 
	int i, disr = DISR;

	struct imx_dma_channel *channel;

	unsigned int err_mask = DBTOSR | DRTOSR | DSESR | DBOSR;

	int errcode;



	DISR = disr;

	DISR = disr & err_mask;

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

		channel = &imx_dma_channels[i];



		if ((err_mask & 1 << i) && channel->name

		    && channel->err_handler) {

			channel->err_handler(i, channel->data, regs);

		if(!(err_mask & (1 << i)))

			continue;

		}



		imx_dma_channels[i].sg = NULL;

		channel = &imx_dma_channels[i];

		errcode = 0;



		if (DBTOSR & (1 << i)) {

			printk(KERN_WARNING

			       "Burst timeout on channel %d (%s)\n",

			       i, channel->name);

			DBTOSR |= (1 << i);

			DBTOSR = (1 << i);

			errcode |= IMX_DMA_ERR_BURST;

		}

		if (DRTOSR & (1 << i)) {

			printk(KERN_WARNING

			       "Request timeout on channel %d (%s)\n",

			       i, channel->name);

			DRTOSR |= (1 << i);

			DRTOSR = (1 << i);

			errcode |= IMX_DMA_ERR_REQUEST;

		}

		if (DSESR & (1 << i)) {

			printk(KERN_WARNING

			       "Transfer timeout on channel %d (%s)\n",

			       i, channel->name);

			DSESR |= (1 << i);

			DSESR = (1 << i);

			errcode |= IMX_DMA_ERR_TRANSFER;

		}

		if (DBOSR & (1 << i)) {

			printk(KERN_WARNING

			       "Buffer overflow timeout on channel %d (%s)\n",

			       i, channel->name);

			DBOSR |= (1 << i);

			DBOSR = (1 << i);

			errcode |= IMX_DMA_ERR_BUFFER;

		}



		/*

		 * The cleaning of @sg field would be questionable

		 * there, because its value can help to compute

		 * remaining/transfered bytes count in the handler

		 */

		/*imx_dma_channels[i].sg = NULL;*/



		if (channel->name && channel->err_handler) {

			channel->err_handler(i, channel->data, regs, errcode);

			continue;

		}



		imx_dma_channels[i].sg = NULL;



		printk(KERN_WARNING

		       "DMA timeout on channel %d (%s) -%s%s%s%s\n",

		       i, channel->name,

		       errcode&IMX_DMA_ERR_BURST?    " burst":"",

		       errcode&IMX_DMA_ERR_REQUEST?  " request":"",

		       errcode&IMX_DMA_ERR_TRANSFER? " transfer":"",

		       errcode&IMX_DMA_ERR_BUFFER?   " buffer":"");

	}

	return IRQ_HANDLED;

}

include/asm-arm/arch-imx/imx-dma.h

+6 −2
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ 
struct imx_dma_channel {

	const char *name;

	void (*irq_handler) (int, void *, struct pt_regs *);

	void (*err_handler) (int, void *, struct pt_regs *);

	void (*err_handler) (int, void *, struct pt_regs *, int errcode);

	void *data;

	dmamode_t  dma_mode;

	struct scatterlist *sg;
@@ -58,6 +58,10 @@ struct imx_dma_channel { 


extern struct imx_dma_channel imx_dma_channels[IMX_DMA_CHANNELS];



#define IMX_DMA_ERR_BURST     1

#define IMX_DMA_ERR_REQUEST   2

#define IMX_DMA_ERR_TRANSFER  4

#define IMX_DMA_ERR_BUFFER    8



/* The type to distinguish channel numbers parameter from ordinal int type */

typedef int imx_dmach_t;
@@ -74,7 +78,7 @@ imx_dma_setup_sg(imx_dmach_t dma_ch, 
int

imx_dma_setup_handlers(imx_dmach_t dma_ch,

		void (*irq_handler) (int, void *, struct pt_regs *),

		void (*err_handler) (int, void *, struct pt_regs *), void *data);

		void (*err_handler) (int, void *, struct pt_regs *, int), void *data);



void imx_dma_enable(imx_dmach_t dma_ch);