ixgbe: cleanup checksum to allow error results

Currently the shared code checksum calculation function only
returns a u16 and cannot return an error code. Unfortunately
a variety of errors can happen that completely prevent the
calculation of a checksum. So, change the function return value
from a u16 to an s32 and return a negative value on error, or the
positive checksum value when there is no error.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 54 insertions, 32 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
index 2c77539..7633ba1 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
@@ -1625,7 +1625,7 @@ static void ixgbe_release_eeprom(struct ixgbe_hw *hw)
  *  ixgbe_calc_eeprom_checksum_generic - Calculates and returns the checksum
  *  @hw: pointer to hardware structure
  **/
-u16 ixgbe_calc_eeprom_checksum_generic(struct ixgbe_hw *hw)
+s32 ixgbe_calc_eeprom_checksum_generic(struct ixgbe_hw *hw)
 {
 	u16 i;
 	u16 j;
@@ -1636,7 +1636,7 @@ u16 ixgbe_calc_eeprom_checksum_generic(struct ixgbe_hw *hw)
 
 	/* Include 0x0-0x3F in the checksum */
 	for (i = 0; i < IXGBE_EEPROM_CHECKSUM; i++) {
-		if (hw->eeprom.ops.read(hw, i, &word) != 0) {
+		if (hw->eeprom.ops.read(hw, i, &word)) {
 			hw_dbg(hw, "EEPROM read failed\n");
 			break;
 		}
@@ -1645,24 +1645,35 @@ u16 ixgbe_calc_eeprom_checksum_generic(struct ixgbe_hw *hw)
 
 	/* Include all data from pointers except for the fw pointer */
 	for (i = IXGBE_PCIE_ANALOG_PTR; i < IXGBE_FW_PTR; i++) {
-		hw->eeprom.ops.read(hw, i, &pointer);
+		if (hw->eeprom.ops.read(hw, i, &pointer)) {
+			hw_dbg(hw, "EEPROM read failed\n");
+			return IXGBE_ERR_EEPROM;
+		}
+
+		/* If the pointer seems invalid */
+		if (pointer == 0xFFFF || pointer == 0)
+			continue;
+
+		if (hw->eeprom.ops.read(hw, pointer, &length)) {
+			hw_dbg(hw, "EEPROM read failed\n");
+			return IXGBE_ERR_EEPROM;
+		}
 
-		/* Make sure the pointer seems valid */
-		if (pointer != 0xFFFF && pointer != 0) {
-			hw->eeprom.ops.read(hw, pointer, &length);
+		if (length == 0xFFFF || length == 0)
+			continue;
 
-			if (length != 0xFFFF && length != 0) {
-				for (j = pointer+1; j <= pointer+length; j++) {
-					hw->eeprom.ops.read(hw, j, &word);
-					checksum += word;
-				}
+		for (j = pointer + 1; j <= pointer + length; j++) {
+			if (hw->eeprom.ops.read(hw, j, &word)) {
+				hw_dbg(hw, "EEPROM read failed\n");
+				return IXGBE_ERR_EEPROM;
 			}
+			checksum += word;
 		}
 	}
 
 	checksum = (u16)IXGBE_EEPROM_SUM - checksum;
 
-	return checksum;
+	return (s32)checksum;
 }
 
 /**
@@ -1686,26 +1697,33 @@ s32 ixgbe_validate_eeprom_checksum_generic(struct ixgbe_hw *hw,
 	 * EEPROM read fails
 	 */
 	status = hw->eeprom.ops.read(hw, 0, &checksum);
+	if (status) {
+		hw_dbg(hw, "EEPROM read failed\n");
+		return status;
+	}
 
-	if (status == 0) {
-		checksum = hw->eeprom.ops.calc_checksum(hw);
+	status = hw->eeprom.ops.calc_checksum(hw);
+	if (status < 0)
+		return status;
 
-		hw->eeprom.ops.read(hw, IXGBE_EEPROM_CHECKSUM, &read_checksum);
+	checksum = (u16)(status & 0xffff);
 
-		/*
-		 * Verify read checksum from EEPROM is the same as
-		 * calculated checksum
-		 */
-		if (read_checksum != checksum)
-			status = IXGBE_ERR_EEPROM_CHECKSUM;
-
-		/* If the user cares, return the calculated checksum */
-		if (checksum_val)
-			*checksum_val = checksum;
-	} else {
+	status = hw->eeprom.ops.read(hw, IXGBE_EEPROM_CHECKSUM, &read_checksum);
+	if (status) {
 		hw_dbg(hw, "EEPROM read failed\n");
+		return status;
 	}
 
+	/* Verify read checksum from EEPROM is the same as
+	 * calculated checksum
+	 */
+	if (read_checksum != checksum)
+		status = IXGBE_ERR_EEPROM_CHECKSUM;
+
+	/* If the user cares, return the calculated checksum */
+	if (checksum_val)
+		*checksum_val = checksum;
+
 	return status;
 }
 
@@ -1724,15 +1742,19 @@ s32 ixgbe_update_eeprom_checksum_generic(struct ixgbe_hw *hw)
 	 * EEPROM read fails
 	 */
 	status = hw->eeprom.ops.read(hw, 0, &checksum);
-
-	if (status == 0) {
-		checksum = hw->eeprom.ops.calc_checksum(hw);
-		status = hw->eeprom.ops.write(hw, IXGBE_EEPROM_CHECKSUM,
-					      checksum);
-	} else {
+	if (status) {
 		hw_dbg(hw, "EEPROM read failed\n");
+		return status;
 	}
 
+	status = hw->eeprom.ops.calc_checksum(hw);
+	if (status < 0)
+		return status;
+
+	checksum = (u16)(status & 0xffff);
+
+	status = hw->eeprom.ops.write(hw, IXGBE_EEPROM_CHECKSUM, checksum);
+
 	return status;
 }