[PATCH net] net: e1000e: Recover at least in-memory copy of NVM checksum

[Thomas Bogendoerfer]

Commit 4051f68318ca ("e1000e: Do not take care about recovery NVM
checksum") causes a regression for systems with a broken NVM checksum
and hardware which is not able to update the NVM. Before the change the
in-memory copy was correct even the NVM update doesn't work, which is
good enough for the driver to work again.

See

https://bugzilla.opensuse.org/show_bug.cgi?id=1191663

for more details.

This patch reverts the change and moves the check for hardware without
NVM update capability right before the real flash update.

Fixes: 4051f68318ca ("e1000e: Do not take care about recovery NVM checksum")
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@xxxxxxx>
---
 drivers/net/ethernet/intel/e1000e/ich8lan.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index 5e4fc9b4e2ad..613a60f24ba6 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -3808,6 +3808,9 @@ static s32 e1000_update_nvm_checksum_spt(struct e1000_hw *hw)
 	if (nvm->type != e1000_nvm_flash_sw)
 		goto out;
 
+	if (hw->mac.type >= e1000_pch_cnp)
+		goto out;
+
 	nvm->ops.acquire(hw);
 
 	/* We're writing to the opposite bank so if we're on bank 1,
@@ -4136,17 +4139,13 @@ static s32 e1000_validate_nvm_checksum_ich8lan(struct e1000_hw *hw)
 		return ret_val;
 
 	if (!(data & valid_csum_mask)) {
-		e_dbg("NVM Checksum Invalid\n");
-
-		if (hw->mac.type < e1000_pch_cnp) {
-			data |= valid_csum_mask;
-			ret_val = e1000_write_nvm(hw, word, 1, &data);
-			if (ret_val)
-				return ret_val;
-			ret_val = e1000e_update_nvm_checksum(hw);
-			if (ret_val)
-				return ret_val;
-		}
+		data |= valid_csum_mask;
+		ret_val = e1000_write_nvm(hw, word, 1, &data);
+		if (ret_val)
+			return ret_val;
+		ret_val = e1000e_update_nvm_checksum(hw);
+		if (ret_val)
+			return ret_val;
 	}
 
 	return e1000e_validate_nvm_checksum_generic(hw);
-- 
2.29.2