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Commit fb45d323 authored by Maxim Levitsky's avatar Maxim Levitsky Committed by David Woodhouse
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mtd: r852: Few fixes for problems that occur when card is rapidly inserted/removed. 



First don't enable card detection logic to early. Second be very careful with
DMA engine, to be sure it doesn't write to kernel memory driver doesn't own.

Signed-off-by: default avatarMaxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent d4080cb3

drivers/mtd/nand/r852.c

+17 −4
Original line number Original line Diff line number Diff line
@@ -96,14 +96,21 @@ static void r852_dma_enable(struct r852_device *dev) 
	if (dev->dma_dir)

	if (dev->dma_dir)

		dma_reg |= R852_DMA_READ;

		dma_reg |= R852_DMA_READ;





	if (dev->dma_state == DMA_INTERNAL)

	if (dev->dma_state == DMA_INTERNAL) {

		dma_reg |= R852_DMA_INTERNAL;

		dma_reg |= R852_DMA_INTERNAL;

	else {

		/* Precaution to make sure HW doesn't write */

			/* to random kernel memory */

		r852_write_reg_dword(dev, R852_DMA_ADDR,

			cpu_to_le32(dev->phys_bounce_buffer));

	} else {

		dma_reg |= R852_DMA_MEMORY;

		dma_reg |= R852_DMA_MEMORY;

		r852_write_reg_dword(dev, R852_DMA_ADDR,

		r852_write_reg_dword(dev, R852_DMA_ADDR,

			cpu_to_le32(dev->phys_dma_addr));

			cpu_to_le32(dev->phys_dma_addr));

	}

	}





	/* Precaution: make sure write reached the device */

	r852_read_reg_dword(dev, R852_DMA_ADDR);



	r852_write_reg_dword(dev, R852_DMA_SETTINGS, dma_reg);

	r852_write_reg_dword(dev, R852_DMA_SETTINGS, dma_reg);





	/* Set dma irq */

	/* Set dma irq */
@@ -129,6 +136,11 @@ static void r852_dma_done(struct r852_device *dev, int error) 
	r852_write_reg_dword(dev, R852_DMA_SETTINGS, 0);

	r852_write_reg_dword(dev, R852_DMA_SETTINGS, 0);

	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE, 0);

	r852_write_reg_dword(dev, R852_DMA_IRQ_ENABLE, 0);





	/* Precaution to make sure HW doesn't write to random kernel memory */

	r852_write_reg_dword(dev, R852_DMA_ADDR,

		cpu_to_le32(dev->phys_bounce_buffer));

	r852_read_reg_dword(dev, R852_DMA_ADDR);



	dev->dma_error = error;

	dev->dma_error = error;

	dev->dma_stage = 0;

	dev->dma_stage = 0;
@@ -579,6 +591,7 @@ void r852_card_update_present(struct r852_device *dev) 
void r852_update_card_detect(struct r852_device *dev)

void r852_update_card_detect(struct r852_device *dev)

{

{

	int card_detect_reg = r852_read_reg(dev, R852_CARD_IRQ_ENABLE);

	int card_detect_reg = r852_read_reg(dev, R852_CARD_IRQ_ENABLE);

	dev->card_unstable = 0;





	card_detect_reg &= ~(R852_CARD_IRQ_REMOVE | R852_CARD_IRQ_INSERT);

	card_detect_reg &= ~(R852_CARD_IRQ_REMOVE | R852_CARD_IRQ_INSERT);

	card_detect_reg |= R852_CARD_IRQ_GENABLE;

	card_detect_reg |= R852_CARD_IRQ_GENABLE;
@@ -690,10 +703,10 @@ void r852_card_detect_work(struct work_struct *work) 
	struct r852_device *dev =

	struct r852_device *dev =

		container_of(work, struct r852_device, card_detect_work.work);

		container_of(work, struct r852_device, card_detect_work.work);





	r852_update_card_detect(dev);

	r852_card_update_present(dev);

	dev->card_unstable = 0;

	dev->card_unstable = 0;





	/* false alarm */

	/* False alarm */

	if (dev->card_detected == dev->card_registred)

	if (dev->card_detected == dev->card_registred)

		goto exit;

		goto exit;