From: Jacek Kowalski jacek@jacekk.info

As described by Vitaly Lifshits:

Starting from Tiger Lake, LAN NVM is locked for writes by SW, so the driver cannot perform checksum validation and correction. This means that all NVM images must leave the factory with correct checksum and checksum valid bit set.

Unfortunately some systems have left the factory with an uninitialized value of 0xFFFF at register address 0x3F (checksum word location). So on Tiger Lake platform we ignore the computed checksum when such condition is encountered.

Signed-off-by: Jacek Kowalski jacek@jacekk.info Tested-by: Vlad URSU vlad@ursu.me Fixes: 4051f68318ca9 ("e1000e: Do not take care about recovery NVM checksum") Cc: stable@vger.kernel.org Reviewed-by: Simon Horman horms@kernel.org Reviewed-by: Vitaly Lifshits vitaly.lifshits@intel.com Tested-by: Mor Bar-Gabay morx.bar.gabay@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com --- drivers/net/ethernet/intel/e1000e/defines.h | 3 +++ drivers/net/ethernet/intel/e1000e/nvm.c | 6 ++++++ 2 files changed, 9 insertions(+)

diff --git a/drivers/net/ethernet/intel/e1000e/defines.h b/drivers/net/ethernet/intel/e1000e/defines.h index 8294a7c4f122..ba331899d186 100644 --- a/drivers/net/ethernet/intel/e1000e/defines.h +++ b/drivers/net/ethernet/intel/e1000e/defines.h @@ -638,6 +638,9 @@ /* For checksumming, the sum of all words in the NVM should equal 0xBABA. */ #define NVM_SUM 0xBABA

+/* Uninitialized ("empty") checksum word value */ +#define NVM_CHECKSUM_UNINITIALIZED 0xFFFF + /* PBA (printed board assembly) number words */ #define NVM_PBA_OFFSET_0 8 #define NVM_PBA_OFFSET_1 9 diff --git a/drivers/net/ethernet/intel/e1000e/nvm.c b/drivers/net/ethernet/intel/e1000e/nvm.c index e609f4df86f4..16369e6d245a 100644 --- a/drivers/net/ethernet/intel/e1000e/nvm.c +++ b/drivers/net/ethernet/intel/e1000e/nvm.c @@ -558,6 +558,12 @@ s32 e1000e_validate_nvm_checksum_generic(struct e1000_hw *hw) checksum += nvm_data; }

+ if (hw->mac.type == e1000_pch_tgp && + nvm_data == NVM_CHECKSUM_UNINITIALIZED) { + e_dbg("Uninitialized NVM Checksum on TGP platform - ignoring\n"); + return 0; + } + if (checksum != (u16)NVM_SUM) { e_dbg("NVM Checksum Invalid\n"); return -E1000_ERR_NVM;