diff options
| -rw-r--r-- | drivers/dma/xilinx/xilinx_dma.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c index 0817b74f7..cffe7c6fa 100644 --- a/drivers/dma/xilinx/xilinx_dma.c +++ b/drivers/dma/xilinx/xilinx_dma.c @@ -756,15 +756,25 @@ xilinx_aximcdma_alloc_tx_segment(struct xilinx_dma_chan *chan) return segment; } -static void xilinx_dma_clean_hw_desc(struct xilinx_axidma_desc_hw *hw) +static void xilinx_dma_clean_hw_desc(struct xilinx_dma_chan *chan, + struct xilinx_axidma_tx_segment *segment) { - u32 next_desc = hw->next_desc; - u32 next_desc_msb = hw->next_desc_msb; + dma_addr_t next; + u32 i; - memset(hw, 0, sizeof(struct xilinx_axidma_desc_hw)); + /* + * Restore the buffer descriptor's next descriptor pointer to the value + * set up in xilinx_dma_alloc_chan_resources(). Otherwise using the DMA + * in cyclic mode leaves the next descriptor pointer altered and + * prevents subsequent non-cyclic transfers. + */ + i = segment - chan->seg_v; + next = chan->seg_p + + sizeof(*chan->seg_v) * ((i + 1) % XILINX_DMA_NUM_DESCS); - hw->next_desc = next_desc; - hw->next_desc_msb = next_desc_msb; + memset(&segment->hw, 0, sizeof(segment->hw)); + segment->hw.next_desc = lower_32_bits(next); + segment->hw.next_desc_msb = upper_32_bits(next); } static void xilinx_mcdma_clean_hw_desc(struct xilinx_aximcdma_desc_hw *hw) @@ -786,7 +796,7 @@ static void xilinx_mcdma_clean_hw_desc(struct xilinx_aximcdma_desc_hw *hw) static void xilinx_dma_free_tx_segment(struct xilinx_dma_chan *chan, struct xilinx_axidma_tx_segment *segment) { - xilinx_dma_clean_hw_desc(&segment->hw); + xilinx_dma_clean_hw_desc(chan, segment); list_add_tail(&segment->node, &chan->free_seg_list); } |