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authorMarek Vasut <marex@denx.de>2012-09-04 06:04:25 +0200
committerVinod Koul <vinod.koul@linux.intel.com>2012-09-14 05:01:47 +0200
commit5e97fa91492b4943f25228e08d24abb31e5bce50 (patch)
tree02495f046ade4a1e99175ba7509ffb5a6b227c7f /drivers/dma/mxs-dma.c
parentdw_dmac: utilize slave_id to pass request line (diff)
downloadlinux-5e97fa91492b4943f25228e08d24abb31e5bce50.tar.xz
linux-5e97fa91492b4943f25228e08d24abb31e5bce50.zip
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: Marek 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: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Diffstat (limited to 'drivers/dma/mxs-dma.c')
-rw-r--r--drivers/dma/mxs-dma.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index 7f41b25805fa..e269325d0f00 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -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);