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

From: Kedareswara rao Appana
Date: Fri Feb 26 2016 - 09:04:51 EST

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@xxxxxxxxxx>
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)

+ /* 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