r8169: improve rtl_set_coalesce

Use FIELD_PREP() to make the code better readable, and avoid the loop.
No functional change intended.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index a81d46abe3c21bde285b0571f5025eb71b9aeb95..4fe8b1d35b696eda860d868a6b318db8f8615e83 100644 (file)
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -235,10 +235,8 @@ enum rtl_registers {
 #define RTL_COALESCE_RX_USECS  GENMASK(7, 4)
 #define RTL_COALESCE_RX_FRAMES GENMASK(3, 0)
 
-#define RTL_COALESCE_MASK      0x0f
-#define RTL_COALESCE_SHIFT     4
-#define RTL_COALESCE_T_MAX     (RTL_COALESCE_MASK)
-#define RTL_COALESCE_FRAME_MAX (RTL_COALESCE_MASK << 2)
+#define RTL_COALESCE_T_MAX     0x0fU
+#define RTL_COALESCE_FRAME_MAX (RTL_COALESCE_T_MAX * 4)
 
        RxDescAddrLow   = 0xe4,
        RxDescAddrHigh  = 0xe8,
@@ -1878,57 +1876,49 @@ static int rtl_coalesce_choose_scale(struct rtl8169_private *tp, u32 usec,
 static int rtl_set_coalesce(struct net_device *dev, struct ethtool_coalesce *ec)
 {
        struct rtl8169_private *tp = netdev_priv(dev);
-       struct {
-               u32 frames;
-               u32 usecs;
-       } coal_settings [] = {
-               { ec->rx_max_coalesced_frames, ec->rx_coalesce_usecs },
-               { ec->tx_max_coalesced_frames, ec->tx_coalesce_usecs }
-       }, *p = coal_settings;
+       u32 tx_fr = ec->tx_max_coalesced_frames;
+       u32 rx_fr = ec->rx_max_coalesced_frames;
+       u32 coal_usec_max, units;
        u16 w = 0, cp01 = 0;
-       u32 coal_usec_max;
-       int scale, i;
+       int scale;
 
        if (rtl_is_8125(tp))
                return -EOPNOTSUPP;
 
+       if (rx_fr > RTL_COALESCE_FRAME_MAX || tx_fr > RTL_COALESCE_FRAME_MAX)
+               return -ERANGE;
+
        coal_usec_max = max(ec->rx_coalesce_usecs, ec->tx_coalesce_usecs);
        scale = rtl_coalesce_choose_scale(tp, coal_usec_max, &cp01);
        if (scale < 0)
                return scale;
 
-       for (i = 0; i < 2; i++, p++) {
-               u32 units;
-
-               /*
-                * accept max_frames=1 we returned in rtl_get_coalesce.
-                * accept it not only when usecs=0 because of e.g. the following scenario:
-                *
-                * - both rx_usecs=0 & rx_frames=0 in hardware (no delay on RX)
-                * - rtl_get_coalesce returns rx_usecs=0, rx_frames=1
-                * - then user does `ethtool -C eth0 rx-usecs 100`
-                *
-                * since ethtool sends to kernel whole ethtool_coalesce
-                * settings, if we want to ignore rx_frames then it has
-                * to be set to 0.
-                */
-               if (p->frames == 1) {
-                       p->frames = 0;
-               }
+       /* Accept max_frames=1 we returned in rtl_get_coalesce. Accept it
+        * not only when usecs=0 because of e.g. the following scenario:
+        *
+        * - both rx_usecs=0 & rx_frames=0 in hardware (no delay on RX)
+        * - rtl_get_coalesce returns rx_usecs=0, rx_frames=1
+        * - then user does `ethtool -C eth0 rx-usecs 100`
+        *
+        * Since ethtool sends to kernel whole ethtool_coalesce settings,
+        * if we want to ignore rx_frames then it has to be set to 0.
+        */
+       if (rx_fr == 1)
+               rx_fr = 0;
+       if (tx_fr == 1)
+               tx_fr = 0;
 
-               units = DIV_ROUND_UP(p->usecs * 1000, scale);
-               if (p->frames > RTL_COALESCE_FRAME_MAX)
-                       return -ERANGE;
+       w |= FIELD_PREP(RTL_COALESCE_TX_FRAMES, DIV_ROUND_UP(tx_fr, 4));
+       w |= FIELD_PREP(RTL_COALESCE_RX_FRAMES, DIV_ROUND_UP(rx_fr, 4));
 
-               w <<= RTL_COALESCE_SHIFT;
-               w |= units;
-               w <<= RTL_COALESCE_SHIFT;
-               w |= DIV_ROUND_UP(p->frames, 4);
-       }
+       units = DIV_ROUND_UP(ec->tx_coalesce_usecs * 1000U, scale);
+       w |= FIELD_PREP(RTL_COALESCE_TX_USECS, units);
+       units = DIV_ROUND_UP(ec->rx_coalesce_usecs * 1000U, scale);
+       w |= FIELD_PREP(RTL_COALESCE_RX_USECS, units);
 
        rtl_lock_work(tp);
 
-       RTL_W16(tp, IntrMitigate, swab16(w));
+       RTL_W16(tp, IntrMitigate, w);
 
        tp->cp_cmd = (tp->cp_cmd & ~INTT_MASK) | cp01;
        RTL_W16(tp, CPlusCmd, tp->cp_cmd);