[PATCH v3 3/4] dmaengine: xilinx_vdma: Fix issues with non-parking mode

Kedareswara rao Appana appana.durga.rao at xilinx.com
Fri Feb 26 06:03:53 PST 2016


This patch fixes issues with the Non-parking mode(Cirular mode).
With the  existing driver in cirular mode if we submit frames less than h/w
configured we simply end-up having misconfigured vdma h/w.
This patch fixes this issue by configuring the frame count register.

Signed-off-by: Kedareswara rao Appana <appanad at xilinx.com>
---
Changes for v3:
---> None.
Changes for v2:
---> splitted the changes into multiple patches.

 drivers/dma/xilinx/xilinx_vdma.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index ce330d4..70b2b32 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -646,6 +646,10 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan)
 	else
 		reg &= ~XILINX_VDMA_DMACR_FRAMECNT_EN;
 
+	/* Configure channel to allow number frame buffers */
+	vdma_ctrl_write(chan, XILINX_VDMA_REG_FRMSTORE,
+			chan->desc_pendingcount);
+
 	/*
 	 * With SG, start with circular mode, so that BDs can be fetched.
 	 * In direct register mode, if not parking, enable circular mode
-- 
2.1.2




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