ixgbe: Add ability to double reset on failure to clear master enable

Double resets are required for recovery from certain error conditions.
Between resets, it is necessary to stall to allow time for any pending HW
events to complete. We use 1usec since that is what is needed for
ixgbe_disable_pcie_master(). The second reset then clears out any effects
of those events.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 15 insertions, 6 deletions

diff --git a/drivers/net/ixgbe/ixgbe_82598.c b/drivers/net/ixgbe/ixgbe_82598.c
index d0f1d9d2c416..291b1e6f85c9 100644
--- a/drivers/net/ixgbe/ixgbe_82598.c
+++ b/drivers/net/ixgbe/ixgbe_82598.c
@@ -770,7 +770,6 @@ static s32 ixgbe_reset_hw_82598(struct ixgbe_hw *hw)
 		else if (phy_status == IXGBE_ERR_SFP_NOT_PRESENT)
 			goto no_phy_reset;
 
-
 		hw->phy.ops.reset(hw);
 	}
 
@@ -779,12 +778,9 @@ no_phy_reset:
 	 * Prevent the PCI-E bus from from hanging by disabling PCI-E master
 	 * access and verify no pending requests before reset
 	 */
-	status = ixgbe_disable_pcie_master(hw);
-	if (status != 0) {
-		status = IXGBE_ERR_MASTER_REQUESTS_PENDING;
-		hw_dbg(hw, "PCI-E Master disable polling has failed.\n");
-	}
+	ixgbe_disable_pcie_master(hw);
 
+mac_reset_top:
 	/*
 	 * Issue global reset to the MAC.  This needs to be a SW reset.
 	 * If link reset is used, it might reset the MAC when mng is using it
@@ -805,6 +801,19 @@ no_phy_reset:
 		hw_dbg(hw, "Reset polling failed to complete.\n");
 	}
 
+	/*
+	 * Double resets are required for recovery from certain error
+	 * conditions.  Between resets, it is necessary to stall to allow time
+	 * for any pending HW events to complete.  We use 1usec since that is
+	 * what is needed for ixgbe_disable_pcie_master().  The second reset
+	 * then clears out any effects of those events.
+	 */
+	if (hw->mac.flags & IXGBE_FLAGS_DOUBLE_RESET_REQUIRED) {
+		hw->mac.flags &= ~IXGBE_FLAGS_DOUBLE_RESET_REQUIRED;
+		udelay(1);
+		goto mac_reset_top;
+	}
+
 	msleep(50);
 
 	gheccr = IXGBE_READ_REG(hw, IXGBE_GHECCR);