From 049c0d577d63c6a95edd5f59fa192f89f2674a64 Mon Sep 17 00:00:00 2001
From: Srikanth Thokala <srikanth.thokala@xilinx.com>
Date: Wed, 5 Nov 2014 20:37:00 +0200
Subject: dmaengine: xilinx: vdma: Check if the segment list is empty in a
descriptor
The segment list in a descriptor should be checked for empty, else
it will try to access invalid address for the first call. This
patch fixes this issue.
Signed-off-by: Srikanth Thokala <sthokal@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
---
drivers/dma/xilinx/xilinx_vdma.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index a6e64767186e..10937945a527 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -971,9 +971,11 @@ xilinx_vdma_dma_prep_interleaved(struct dma_chan *dchan,
hw->buf_addr = xt->src_start;
/* Link the previous next descriptor to current */
- prev = list_last_entry(&desc->segments,
- struct xilinx_vdma_tx_segment, node);
- prev->hw.next_desc = segment->phys;
+ if (!list_empty(&desc->segments)) {
+ prev = list_last_entry(&desc->segments,
+ struct xilinx_vdma_tx_segment, node);
+ prev->hw.next_desc = segment->phys;
+ }
/* Insert the segment into the descriptor segments list. */
list_add_tail(&segment->node, &desc->segments);
--
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