[PATCH net-next v2 13/18] net: macb: avoid double endianness swap in macb_set_hwaddr()

[Théo Lebrun]

writel() does a CPU->LE conversion. Drop manual cpu_to_le*() calls.

On little-endian system:
 - cpu_to_le32() is a no-op (LE->LE),
 - writel() is a no-op (LE->LE),
 - dev_addr will therefore not be swapped and written as-is.

On big-endian system:
 - cpu_to_le32() is a swap (BE->LE),
 - writel() is a swap (BE->LE),
 - dev_addr will therefore be swapped twice and written as a BE value.

This was found using sparse:
   ⟩ make C=2 drivers/net/ethernet/cadence/macb_main.o
   warning: incorrect type in assignment (different base types)
      expected unsigned int [usertype] bottom
      got restricted __le32 [usertype]
   warning: incorrect type in assignment (different base types)
      expected unsigned short [usertype] top
      got restricted __le16 [usertype]
   ...

Fixes: 89e5785fc8a6 ("[PATCH] Atmel MACB ethernet driver")
Signed-off-by: Théo Lebrun <theo.lebrun at bootlin.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 578e72c7727d4f578478ff2b3d0a6316327271b1..34223dad2d01ae4bcefc0823c868a67f59435638 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -265,9 +265,9 @@ static void macb_set_hwaddr(struct macb *bp)
 	u32 bottom;
 	u16 top;
 
-	bottom = cpu_to_le32(*((u32 *)bp->dev->dev_addr));
+	bottom = *((u32 *)bp->dev->dev_addr);
 	macb_or_gem_writel(bp, SA1B, bottom);
-	top = cpu_to_le16(*((u16 *)(bp->dev->dev_addr + 4)));
+	top = *((u16 *)(bp->dev->dev_addr + 4));
 	macb_or_gem_writel(bp, SA1T, top);
 
 	if (gem_has_ptp(bp)) {

-- 
2.50.0