Merge tag 'lkdtm-next' of https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux...

[linux-2.6-microblaze.git] / drivers / net / ethernet / cadence / macb_main.c

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 800d5ce..e475be2 100644 (file)
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -1658,6 +1658,7 @@ static void macb_tx_restart(struct macb_queue *queue)
        unsigned int head = queue->tx_head;
        unsigned int tail = queue->tx_tail;
        struct macb *bp = queue->bp;
+       unsigned int head_idx, tbqp;
 
        if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
                queue_writel(queue, ISR, MACB_BIT(TXUBR));
@@ -1665,6 +1666,13 @@ static void macb_tx_restart(struct macb_queue *queue)
        if (head == tail)
                return;
 
+       tbqp = queue_readl(queue, TBQP) / macb_dma_desc_get_size(bp);
+       tbqp = macb_adj_dma_desc_idx(bp, macb_tx_ring_wrap(bp, tbqp));
+       head_idx = macb_adj_dma_desc_idx(bp, macb_tx_ring_wrap(bp, head));
+
+       if (tbqp == head_idx)
+               return;
+
        macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART));
 }