Commit 5e97fa91 authored by Marek Vasut's avatar Marek Vasut Committed by Vinod Koul
Browse files

mxs/dma: Enlarge the CCW descriptor area to 4 pages 



In case of a large SPI flash, the amount of DMA descriptors
available to the DMA driver is not large enough anymore. For
example 8MB SPI flash now needs 129 descriptors to be transfered
in one long read. There are currently 53 descriptors available in
one PAGE_SIZE-big block. Enlarge the allocated descriptor area to
four PAGE_SIZE blocks to fulfill such requirements.

Signed-off-by: default avatarMarek Vasut <marex@denx.de>
Cc: Dan Williams <djbw@fb.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Acked-by: default avatarShawn Guo <shawn.guo@linaro.org>
Signed-off-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
parent 8fccc5bf

drivers/dma/mxs-dma.c

+8 −6
Original line number Diff line number Diff line
@@ -101,7 +101,8 @@ struct mxs_dma_ccw { 
	u32		pio_words[MXS_PIO_WORDS];

};



#define NUM_CCW	(int)(PAGE_SIZE / sizeof(struct mxs_dma_ccw))

#define CCW_BLOCK_SIZE	(4 * PAGE_SIZE)

#define NUM_CCW	(int)(CCW_BLOCK_SIZE / sizeof(struct mxs_dma_ccw))



struct mxs_dma_chan {

	struct mxs_dma_engine		*mxs_dma;
@@ -354,14 +355,15 @@ static int mxs_dma_alloc_chan_resources(struct dma_chan *chan) 


	mxs_chan->chan_irq = data->chan_irq;



	mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,

				&mxs_chan->ccw_phys, GFP_KERNEL);

	mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev,

				CCW_BLOCK_SIZE, &mxs_chan->ccw_phys,

				GFP_KERNEL);

	if (!mxs_chan->ccw) {

		ret = -ENOMEM;

		goto err_alloc;

	}



	memset(mxs_chan->ccw, 0, PAGE_SIZE);

	memset(mxs_chan->ccw, 0, CCW_BLOCK_SIZE);



	if (mxs_chan->chan_irq != NO_IRQ) {

		ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler,
@@ -387,7 +389,7 @@ static int mxs_dma_alloc_chan_resources(struct dma_chan *chan) 
err_clk:

	free_irq(mxs_chan->chan_irq, mxs_dma);

err_irq:

	dma_free_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,

	dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,

			mxs_chan->ccw, mxs_chan->ccw_phys);

err_alloc:

	return ret;
@@ -402,7 +404,7 @@ static void mxs_dma_free_chan_resources(struct dma_chan *chan) 


	free_irq(mxs_chan->chan_irq, mxs_dma);



	dma_free_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,

	dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,

			mxs_chan->ccw, mxs_chan->ccw_phys);



	clk_disable_unprepare(mxs_dma->clk);

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