net: ethernet: mtk_eth_soc: use iopoll.h macro for DMA init

Replace a tight busy-wait loop without a pause with a standard
readx_poll_timeout_atomic routine with a 5 us poll period.

Tested by booting a MT7621 device to ensure the driver initializes
properly.

Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
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 37e50a2..ed4eace 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2033,25 +2033,22 @@ static int mtk_set_features(struct net_device *dev, netdev_features_t features)
 /* wait for DMA to finish whatever it is doing before we start using it again */
 static int mtk_dma_busy_wait(struct mtk_eth *eth)
 {
-       unsigned long t_start = jiffies;
+       unsigned int reg;
+       int ret;
+       u32 val;
 
-       while (1) {
-               if (MTK_HAS_CAPS(eth->soc->caps, MTK_QDMA)) {
-                       if (!(mtk_r32(eth, MTK_QDMA_GLO_CFG) &
-                             (MTK_RX_DMA_BUSY | MTK_TX_DMA_BUSY)))
-                               return 0;
-               } else {
-                       if (!(mtk_r32(eth, MTK_PDMA_GLO_CFG) &
-                             (MTK_RX_DMA_BUSY | MTK_TX_DMA_BUSY)))
-                               return 0;
-               }
+       if (MTK_HAS_CAPS(eth->soc->caps, MTK_QDMA))
+               reg = MTK_QDMA_GLO_CFG;
+       else
+               reg = MTK_PDMA_GLO_CFG;
 
-               if (time_after(jiffies, t_start + MTK_DMA_BUSY_TIMEOUT))
-                       break;
-       }
+       ret = readx_poll_timeout_atomic(__raw_readl, eth->base + reg, val,
+                                       !(val & (MTK_RX_DMA_BUSY | MTK_TX_DMA_BUSY)),
+                                       5, MTK_DMA_BUSY_TIMEOUT_US);
+       if (ret)
+               dev_err(eth->dev, "DMA init timeout\n");
 
-       dev_err(eth->dev, "DMA init timeout\n");
-       return -1;
+       return ret;
 }
 
 static int mtk_dma_init(struct mtk_eth *eth)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 6b92dd6..11331b4 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -214,7 +214,7 @@
 #define MTK_TX_DMA_BUSY                BIT(1)
 #define MTK_RX_DMA_EN          BIT(2)
 #define MTK_TX_DMA_EN          BIT(0)
-#define MTK_DMA_BUSY_TIMEOUT   HZ
+#define MTK_DMA_BUSY_TIMEOUT_US        1000000
 
 /* QDMA Reset Index Register */
 #define MTK_QDMA_RST_IDX       0x1A08