ixgbe: cleanup some register reads

Remove duplicate inc of hwstats->ruc
Introduce separate loops for 8 and 16 register reads.
Consolidate mac checks under one case.
Make sure registers are cleared on read.

Reported-by: Jonathan Lynch <jonathan.lynch@thenowfactory.com>
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
CC: Jonathan Lynch <jonathan.lynch@thenowfactory.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index a4103efde3632d970e4b2715742371bc253d8405..1e72c00dd7c0518403a01676f6390b2c081b3b4e 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -5463,20 +5463,21 @@ void ixgbe_update_stats(struct ixgbe_adapter *adapter)
        netdev->stats.tx_packets = packets;
 
        hwstats->crcerrs += IXGBE_READ_REG(hw, IXGBE_CRCERRS);
+
+       /* 8 register reads */
        for (i = 0; i < 8; i++) {
                /* for packet buffers not used, the register should read 0 */
                mpc = IXGBE_READ_REG(hw, IXGBE_MPC(i));
                missed_rx += mpc;
                hwstats->mpc[i] += mpc;
                total_mpc += hwstats->mpc[i];
-               if (hw->mac.type == ixgbe_mac_82598EB)
-                       hwstats->rnbc[i] += IXGBE_READ_REG(hw, IXGBE_RNBC(i));
-               hwstats->qptc[i] += IXGBE_READ_REG(hw, IXGBE_QPTC(i));
-               hwstats->qbtc[i] += IXGBE_READ_REG(hw, IXGBE_QBTC(i));
-               hwstats->qprc[i] += IXGBE_READ_REG(hw, IXGBE_QPRC(i));
-               hwstats->qbrc[i] += IXGBE_READ_REG(hw, IXGBE_QBRC(i));
+               hwstats->pxontxc[i] += IXGBE_READ_REG(hw, IXGBE_PXONTXC(i));
+               hwstats->pxofftxc[i] += IXGBE_READ_REG(hw, IXGBE_PXOFFTXC(i));
                switch (hw->mac.type) {
                case ixgbe_mac_82598EB:
+                       hwstats->rnbc[i] += IXGBE_READ_REG(hw, IXGBE_RNBC(i));
+                       hwstats->qbtc[i] += IXGBE_READ_REG(hw, IXGBE_QBTC(i));
+                       hwstats->qbrc[i] += IXGBE_READ_REG(hw, IXGBE_QBRC(i));
                        hwstats->pxonrxc[i] +=
                                IXGBE_READ_REG(hw, IXGBE_PXONRXC(i));
                        break;
@@ -5488,9 +5489,21 @@ void ixgbe_update_stats(struct ixgbe_adapter *adapter)
                default:
                        break;
                }
-               hwstats->pxontxc[i] += IXGBE_READ_REG(hw, IXGBE_PXONTXC(i));
-               hwstats->pxofftxc[i] += IXGBE_READ_REG(hw, IXGBE_PXOFFTXC(i));
        }
+
+       /*16 register reads */
+       for (i = 0; i < 16; i++) {
+               hwstats->qptc[i] += IXGBE_READ_REG(hw, IXGBE_QPTC(i));
+               hwstats->qprc[i] += IXGBE_READ_REG(hw, IXGBE_QPRC(i));
+               if ((hw->mac.type == ixgbe_mac_82599EB) ||
+                   (hw->mac.type == ixgbe_mac_X540)) {
+                       hwstats->qbtc[i] += IXGBE_READ_REG(hw, IXGBE_QBTC_L(i));
+                       IXGBE_READ_REG(hw, IXGBE_QBTC_H(i)); /* to clear */
+                       hwstats->qbrc[i] += IXGBE_READ_REG(hw, IXGBE_QBRC_L(i));
+                       IXGBE_READ_REG(hw, IXGBE_QBRC_H(i)); /* to clear */
+               }
+       }
+
        hwstats->gprc += IXGBE_READ_REG(hw, IXGBE_GPRC);
        /* work around hardware counting issue */
        hwstats->gprc -= missed_rx;
@@ -5550,7 +5563,6 @@ void ixgbe_update_stats(struct ixgbe_adapter *adapter)
        hwstats->lxontxc += lxon;
        lxoff = IXGBE_READ_REG(hw, IXGBE_LXOFFTXC);
        hwstats->lxofftxc += lxoff;
-       hwstats->ruc += IXGBE_READ_REG(hw, IXGBE_RUC);
        hwstats->gptc += IXGBE_READ_REG(hw, IXGBE_GPTC);
        hwstats->mptc += IXGBE_READ_REG(hw, IXGBE_MPTC);
        /*