When VDMA is configured for more than one frame in the h/w
for example h/w is configured for n number of frames and user
Submits n number of frames and triggered the DMA using issue_pending API.
In the current driver flow we are submitting one frame at a time
but we should submit all the n number of frames at one time as the h/w
Is configured for n number of frames.

This patch fixes this issue.

Signed-off-by: Kedareswara rao Appana <appa...@xilinx.com>
---
Changes for v2:
---> Fixed race conditions in the driver as suggested by Jose Abreu
---> Fixed unnecessray if else checks in the vdma_start_transfer
     as suggested by Laurent Pinchart.

 drivers/dma/xilinx/xilinx_dma.c | 54 +++++++++++++++++++++++------------------
 1 file changed, 31 insertions(+), 23 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index be7eb41..cf9edd8 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -1052,25 +1052,38 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
        if (chan->has_sg) {
                dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
                                tail_segment->phys);
+               list_splice_tail_init(&chan->pending_list, &chan->active_list);
+               chan->desc_pendingcount = 0;
        } else {
                struct xilinx_vdma_tx_segment *segment, *last = NULL;
-               int i = 0;
+               int i = 0, j = 0;
 
                if (chan->desc_submitcount < chan->num_frms)
                        i = chan->desc_submitcount;
 
-               list_for_each_entry(segment, &desc->segments, node) {
-                       if (chan->ext_addr)
-                               vdma_desc_write_64(chan,
-                                       XILINX_VDMA_REG_START_ADDRESS_64(i++),
-                                       segment->hw.buf_addr,
-                                       segment->hw.buf_addr_msb);
-                       else
-                               vdma_desc_write(chan,
-                                       XILINX_VDMA_REG_START_ADDRESS(i++),
-                                       segment->hw.buf_addr);
-
-                       last = segment;
+               for (j = 0; j < chan->num_frms; ) {
+                       list_for_each_entry(segment, &desc->segments, node) {
+                               if (chan->ext_addr)
+                                       vdma_desc_write_64(chan,
+                                         XILINX_VDMA_REG_START_ADDRESS_64(i++),
+                                         segment->hw.buf_addr,
+                                         segment->hw.buf_addr_msb);
+                               else
+                                       vdma_desc_write(chan,
+                                           XILINX_VDMA_REG_START_ADDRESS(i++),
+                                           segment->hw.buf_addr);
+
+                               last = segment;
+                       }
+                       list_del(&desc->node);
+                       list_add_tail(&desc->node, &chan->active_list);
+                       j++;
+                       if (list_empty(&chan->pending_list) ||
+                           (i == chan->num_frms))
+                               break;
+                       desc = list_first_entry(&chan->pending_list,
+                                               struct xilinx_dma_tx_descriptor,
+                                               node);
                }
 
                if (!last)
@@ -1081,20 +1094,14 @@ static void xilinx_vdma_start_transfer(struct 
xilinx_dma_chan *chan)
                vdma_desc_write(chan, XILINX_DMA_REG_FRMDLY_STRIDE,
                                last->hw.stride);
                vdma_desc_write(chan, XILINX_DMA_REG_VSIZE, last->hw.vsize);
-       }
 
-       chan->idle = false;
-       if (!chan->has_sg) {
-               list_del(&desc->node);
-               list_add_tail(&desc->node, &chan->active_list);
-               chan->desc_submitcount++;
-               chan->desc_pendingcount--;
+               chan->desc_submitcount += j;
+               chan->desc_pendingcount -= j;
                if (chan->desc_submitcount == chan->num_frms)
                        chan->desc_submitcount = 0;
-       } else {
-               list_splice_tail_init(&chan->pending_list, &chan->active_list);
-               chan->desc_pendingcount = 0;
        }
+
+       chan->idle = false;
 }
 
 /**
@@ -1342,6 +1349,7 @@ static int xilinx_dma_reset(struct xilinx_dma_chan *chan)
 
        chan->err = false;
        chan->idle = true;
+       chan->desc_submitcount = 0;
 
        return err;
 }
-- 
2.1.2

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