[PATCH net-next v1 1/1] net: dl2k: Use proper conversion of dev_addr before IO to device

From: Andy Shevchenko
Date: Fri Dec 08 2023 - 10:33:37 EST


The driver is using iowriteXX()/ioreadXX() APIs which are LE IO
accessors simplified as

1. Convert given value _from_ CPU _to_ LE
2. Write it to the device as is

The dev_addr is a byte stream, but because the driver uses 16-bit
IO accessors, it wants to perform double conversion on BE CPUs,
but it took it wrong, as it effectivelly does two times _from_ CPU
_to_ LE. What it has to do is to consider dev_addr as an array of
LE16 and hence do _from_ LE _to_ CPU conversion, followed by implied
_from_ CPU _to_ LE in the iowrite16().

To achieve that, use get_unaligned_le16(). This will make it correct
and allows to avoid sparse warning as reported by LKP.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202312030058.hfZPTXd7-lkp@xxxxxxxxx/
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/net/ethernet/dlink/dl2k.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/dlink/dl2k.c b/drivers/net/ethernet/dlink/dl2k.c
index db6615aa921b..7bfeae04b52b 100644
--- a/drivers/net/ethernet/dlink/dl2k.c
+++ b/drivers/net/ethernet/dlink/dl2k.c
@@ -565,8 +565,7 @@ static void rio_hw_init(struct net_device *dev)
* too. However, it doesn't work on IP1000A so we use 16-bit access.
*/
for (i = 0; i < 3; i++)
- dw16(StationAddr0 + 2 * i,
- cpu_to_le16(((const u16 *)dev->dev_addr)[i]));
+ dw16(StationAddr0 + 2 * i, get_unaligned_le16(&dev->dev_addr[2 * i]));

set_multicast (dev);
if (np->coalesce) {
--
2.43.0.rc1.1.gbec44491f096