From: Srikanth Thokala Date: Wed, 5 Nov 2014 18:37:00 +0000 (+0200) Subject: dmaengine: xilinx: vdma: Check if the segment list is empty in a descriptor X-Git-Tag: v3.19-rc1~100^2~26 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=049c0d577d63c6a95edd5f59fa192f89f2674a64;p=karo-tx-linux.git 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 Signed-off-by: Michal Simek Signed-off-by: Vinod Koul --- 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);