If the hardware is configured for Scatter Gather(SG) mode,
and hardware is idle, in the control register SG mode bit
must be set to a 0 then back to 1 by the software, to force
the CDMA SG engine to use a new value written to the CURDESC_PNTR
register, failure to do so could result errors from the dmaengine.
This patch updates the same.
Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx>
---
Changes for v2:
--> Improved commit message title and description
as suggested by Vinod.
drivers/dma/xilinx/xilinx_dma.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 21ac954..8467671 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -1204,6 +1204,12 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
}
if (chan->has_sg) {
+ dma_ctrl_clr(chan, XILINX_DMA_REG_DMACR,
+ XILINX_CDMA_CR_SGMODE);
+
+ dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
+ XILINX_CDMA_CR_SGMODE);
+
xilinx_write(chan, XILINX_DMA_REG_CURDESC,
head_desc->async_tx.phys);
@@ -2052,6 +2058,10 @@ static int xilinx_dma_terminate_all(struct dma_chan *dchan)
chan->cyclic = false;
}
+ if ((chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) && chan->has_sg)
+ dma_ctrl_clr(chan, XILINX_DMA_REG_DMACR,
+ XILINX_CDMA_CR_SGMODE);
+
return 0;
}
--
2.7.4
--
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