net: mediatek: fix threshold value

The logic to calculate the threshold value for stopping the TX queue is
bad. Currently it will always use 1/2 of the rings size, which is way too
much. Set the threshold to MAX_SKB_FRAGS. This makes sure that the queue
is stopped when there is not enough room to accept an additional segment. 

Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index e3dadae..032939d 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1033,8 +1033,7 @@ static int mtk_tx_alloc(struct mtk_eth *eth)
        atomic_set(&ring->free_count, MTK_DMA_SIZE - 2);
        ring->next_free = &ring->dma[0];
        ring->last_free = &ring->dma[MTK_DMA_SIZE - 2];
-       ring->thresh = max((unsigned long)MTK_DMA_SIZE >> 2,
-                             MAX_SKB_FRAGS);
+       ring->thresh = MAX_SKB_FRAGS;
 
        /* make sure that all changes to the dma ring are flushed before we
         * continue