ixgbe: Add register wait for slow links

Use a new register to wait for previous register writes to complete
before issuing a register read. This is needed when slower links
are in use.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@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 657e999..517f06e 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -371,6 +371,27 @@ u32 ixgbe_read_reg(struct ixgbe_hw *hw, u32 reg)
 
        if (ixgbe_removed(reg_addr))
                return IXGBE_FAILED_READ_REG;
+       if (unlikely(hw->phy.nw_mng_if_sel &
+                    IXGBE_NW_MNG_IF_SEL_ENABLE_10_100M)) {
+               struct ixgbe_adapter *adapter;
+               int i;
+
+               for (i = 0; i < 200; ++i) {
+                       value = readl(reg_addr + IXGBE_MAC_SGMII_BUSY);
+                       if (likely(!value))
+                               goto writes_completed;
+                       if (value == IXGBE_FAILED_READ_REG) {
+                               ixgbe_remove_adapter(hw);
+                               return IXGBE_FAILED_READ_REG;
+                       }
+                       udelay(5);
+               }
+
+               adapter = hw->back;
+               e_warn(hw, "register writes incomplete %08x\n", value);
+       }
+
+writes_completed:
        value = readl(reg_addr + reg);
        if (unlikely(value == IXGBE_FAILED_READ_REG))
                ixgbe_check_remove(hw, reg);

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
index ba3b837..29a1c42 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
@@ -1131,6 +1131,7 @@ struct ixgbe_thermal_sensor_data {
 #define IXGBE_XPCSS     0x04290
 #define IXGBE_MFLCN     0x04294
 #define IXGBE_SERDESC   0x04298
+#define IXGBE_MAC_SGMII_BUSY 0x04298
 #define IXGBE_MACS      0x0429C
 #define IXGBE_AUTOC     0x042A0
 #define IXGBE_LINKS     0x042A4