[PATCH] driver:net:stmmac: Disable DMA store and forward mode if platform data force_sf_dma_mode is negative.

[Sonic Zhang <sonic.adi@gmail.com>]

From: Sonic Zhang <sonic.zhang@analog.com>

Some synopsys ip implementation doesn't support DMA store and forward mode,
such as BF60x. So, define force_sf_dma_mode negative to use DMA thresholds only.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index f2ccb36..b0e003a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1157,7 +1157,9 @@ static void free_dma_desc_resources(struct stmmac_priv *priv)
  */
 static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
 {
-	if (likely(priv->plat->force_sf_dma_mode ||
+	if (priv->plat->force_sf_dma_mode < 0)
+		priv->hw->dma->dma_mode(priv->ioaddr, tc, tc);
+	else if (likely(priv->plat->force_sf_dma_mode > 0 ||
 		   ((priv->plat->tx_coe) && (!priv->no_csum_insertion)))) {
 		/*
 		 * In case of GMAC, SF mode can be enabled
-- 
1.8.2.3