net: axienet: Improve DMA error handling

Since 0 is a valid DMA address, we cannot use the physical address to
check whether a TX descriptor is valid and is holding a DMA mapping.

Use the "cntrl" member of the descriptor to make this decision, as it
contains at least the length of the buffer, so 0 points to an
uninitialised buffer.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index 415179cbdc511b6877797bdafe44a9e88f332f90..82ec7deacdfe22daa267bffb70d6b830384ae7ac 100644 (file)
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -571,7 +571,7 @@ static void axienet_start_xmit_done(struct net_device *ndev)
                                DMA_TO_DEVICE);
                if (cur_p->skb)
                        dev_consume_skb_irq(cur_p->skb);
-               /*cur_p->phys = 0;*/
+               cur_p->cntrl = 0;
                cur_p->app0 = 0;
                cur_p->app1 = 0;
                cur_p->app2 = 0;
@@ -1539,7 +1539,7 @@ static void axienet_dma_err_handler(struct work_struct *work)
 
        for (i = 0; i < lp->tx_bd_num; i++) {
                cur_p = &lp->tx_bd_v[i];
-               if (cur_p->phys)
+               if (cur_p->cntrl)
                        dma_unmap_single(ndev->dev.parent, cur_p->phys,
                                         (cur_p->cntrl &
                                          XAXIDMA_BD_CTRL_LENGTH_MASK),