ixgbevf: add wait for Rx queue disable

New function was added to wait for Rx queues to be disabled before
disabling NAPI. This function also allows us to  modify
ixgbevf_rx_desc_queue_enable() to better match ixgbe.  I also cleaned up
some msleep calls to usleep_range while I was in this code anyway.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index b9a78a2..e3493b0 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -1302,27 +1302,51 @@ static void ixgbevf_configure(struct ixgbevf_adapter *adapter)
        }
 }
 
-#define IXGBE_MAX_RX_DESC_POLL 10
-static inline void ixgbevf_rx_desc_queue_enable(struct ixgbevf_adapter *adapter,
-                                               int rxr)
+#define IXGBEVF_MAX_RX_DESC_POLL 10
+static void ixgbevf_rx_desc_queue_enable(struct ixgbevf_adapter *adapter,
+                                        int rxr)
 {
        struct ixgbe_hw *hw = &adapter->hw;
+       int wait_loop = IXGBEVF_MAX_RX_DESC_POLL;
+       u32 rxdctl;
        int j = adapter->rx_ring[rxr].reg_idx;
-       int k;
 
-       for (k = 0; k < IXGBE_MAX_RX_DESC_POLL; k++) {
-               if (IXGBE_READ_REG(hw, IXGBE_VFRXDCTL(j)) & IXGBE_RXDCTL_ENABLE)
-                       break;
-               else
-                       msleep(1);
-       }
-       if (k >= IXGBE_MAX_RX_DESC_POLL) {
-               hw_dbg(hw, "RXDCTL.ENABLE on Rx queue %d "
-                      "not set within the polling period\n", rxr);
-       }
+       do {
+               usleep_range(1000, 2000);
+               rxdctl = IXGBE_READ_REG(hw, IXGBE_VFRXDCTL(j));
+       } while (--wait_loop && !(rxdctl & IXGBE_RXDCTL_ENABLE));
+
+       if (!wait_loop)
+               hw_dbg(hw, "RXDCTL.ENABLE queue %d not set while polling\n",
+                      rxr);
+
+       ixgbevf_release_rx_desc(&adapter->hw, &adapter->rx_ring[rxr],
+                               (adapter->rx_ring[rxr].count - 1));
+}
 
-       ixgbevf_release_rx_desc(hw, &adapter->rx_ring[rxr],
-                               adapter->rx_ring[rxr].count - 1);
+static void ixgbevf_disable_rx_queue(struct ixgbevf_adapter *adapter,
+                                    struct ixgbevf_ring *ring)
+{
+       struct ixgbe_hw *hw = &adapter->hw;
+       int wait_loop = IXGBEVF_MAX_RX_DESC_POLL;
+       u32 rxdctl;
+       u8 reg_idx = ring->reg_idx;
+
+       rxdctl = IXGBE_READ_REG(hw, IXGBE_VFRXDCTL(reg_idx));
+       rxdctl &= ~IXGBE_RXDCTL_ENABLE;
+
+       /* write value back with RXDCTL.ENABLE bit cleared */
+       IXGBE_WRITE_REG(hw, IXGBE_VFRXDCTL(reg_idx), rxdctl);
+
+       /* the hardware may take up to 100us to really disable the rx queue */
+       do {
+               udelay(10);
+               rxdctl = IXGBE_READ_REG(hw, IXGBE_VFRXDCTL(reg_idx));
+       } while (--wait_loop && (rxdctl & IXGBE_RXDCTL_ENABLE));
+
+       if (!wait_loop)
+               hw_dbg(hw, "RXDCTL.ENABLE queue %d not cleared while polling\n",
+                      reg_idx);
 }
 
 static void ixgbevf_save_reset_stats(struct ixgbevf_adapter *adapter)
@@ -1654,7 +1678,10 @@ void ixgbevf_down(struct ixgbevf_adapter *adapter)
 
        /* signal that we are down to the interrupt handler */
        set_bit(__IXGBEVF_DOWN, &adapter->state);
-       /* disable receives */
+
+       /* disable all enabled rx queues */
+       for (i = 0; i < adapter->num_rx_queues; i++)
+               ixgbevf_disable_rx_queue(adapter, &adapter->rx_ring[i]);
 
        netif_tx_disable(netdev);