[PATCH 5.12 033/242] igb: fix assignment on big endian machines

Greg Kroah-Hartman
2021-07-15T19:07:58Z

From: Jesse Brandeburg <jesse.brandeburg@intel.com>

[ Upstream commit b514958dd1a3bd57638b0e63b8e5152b1960e6aa ]

The igb driver was trying hard to be sparse correct, but somehow
ended up converting a variable into little endian order and then
tries to OR something with it.

A much plainer way of doing things is to leave all variables and
OR operations in CPU (non-endian) mode, and then convert to
little endian only once, which is what this change does.

This probably fixes a bug that might have been seen only on
big endian systems.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Dave Switzer <david.switzer@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/igb/igb_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 894b9b87dba1..434220a342df 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -6277,12 +6277,12 @@ int igb_xmit_xdp_ring(struct igb_adapter *adapter,
cmd_type |= len | IGB_TXD_DCMD;
tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);

- olinfo_status = cpu_to_le32(len << E1000_ADVTXD_PAYLEN_SHIFT);
+ olinfo_status = len << E1000_ADVTXD_PAYLEN_SHIFT;
/* 82575 requires a unique index per ring */
if (test_bit(IGB_RING_FLAG_TX_CTX_IDX, &tx_ring->flags))
olinfo_status |= tx_ring->reg_idx << 4;

- tx_desc->read.olinfo_status = olinfo_status;
+ tx_desc->read.olinfo_status = cpu_to_le32(olinfo_status);

netdev_tx_sent_queue(txring_txq(tx_ring), tx_buffer->bytecount);

--
2.30.2