dmaengine: sprd: Fix the link-list pointer register configuration issue (8b6bc5fd) · Commits · 戴 / test

We will set the link-list pointer register point to next link-list configuration's physical address, which can load DMA configuration from the link-list node automatically. But the link-list node's physical address can be larger than 32bits, and now Spreadtrum DMA driver only supports 32bits physical address, which may cause loading a incorrect DMA configuration when starting the link-list transfer mode. According to the DMA datasheet, we can use SRC_BLK_STEP register (bit28 - bit31) to save the high bits of the link-list node's physical address to fix this issue. Fixes: ("dmaengine: sprd: Support DMA link-list mode") Signed-off-by:

Zhenfang Wang <zhenfang.wang@unisoc.com> Signed-off-by:

Baolin Wang <baolin.wang@linaro.org> Link: https://lore.kernel.org/r/eadfe9295499efa003e1c344e67e2890f9d1d780.1568267061.git.baolin.wang@linaro.org Signed-off-by:

Vinod Koul <vkoul@kernel.org>

drivers/dma/sprd-dma.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -134,6 +134,10 @@
		#define SPRD_DMA_SRC_TRSF_STEP_OFFSET 0
		#define SPRD_DMA_TRSF_STEP_MASK GENMASK(15, 0)

		/* SPRD DMA_SRC_BLK_STEP register definition */
		#define SPRD_DMA_LLIST_HIGH_MASK GENMASK(31, 28)
		#define SPRD_DMA_LLIST_HIGH_SHIFT 28

		/* define DMA channel mode & trigger mode mask */
		#define SPRD_DMA_CHN_MODE_MASK GENMASK(7, 0)
		#define SPRD_DMA_TRG_MODE_MASK GENMASK(7, 0)
		@@ -717,6 +721,7 @@ static int sprd_dma_fill_desc(struct dma_chan *chan,
		u32 int_mode = flags & SPRD_DMA_INT_MASK;
		int src_datawidth, dst_datawidth, src_step, dst_step;
		u32 temp, fix_mode = 0, fix_en = 0;
		phys_addr_t llist_ptr;

		if (dir == DMA_MEM_TO_DEV) {
		src_step = sprd_dma_get_step(slave_cfg->src_addr_width);
		@@ -814,13 +819,16 @@ static int sprd_dma_fill_desc(struct dma_chan *chan,
		* Set the link-list pointer point to next link-list
		* configuration's physical address.
		*/
		hw->llist_ptr = schan->linklist.phy_addr + temp;
		llist_ptr = schan->linklist.phy_addr + temp;
		hw->llist_ptr = lower_32_bits(llist_ptr);
		hw->src_blk_step = (upper_32_bits(llist_ptr) << SPRD_DMA_LLIST_HIGH_SHIFT) &
		SPRD_DMA_LLIST_HIGH_MASK;
		} else {
		hw->llist_ptr = 0;
		hw->src_blk_step = 0;
		}

		hw->frg_step = 0;
		hw->src_blk_step = 0;
		hw->des_blk_step = 0;
		return 0;
		}

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