[PATCH net v2] net: dlink: fix multicast stats being counted incorrectly

`McstFramesRcvdOk` counts the number of received multicast packets, and
it reports the value correctly.

However, reading `McstFramesRcvdOk` clears the register to zero. As a
result, the driver was reporting only the packets since the last read,
instead of the accumulated total.

Fix this by updating the multicast statistics accumulatively instaed of
instantaneously.

Fixes: 3401299a1b9e747cbf7de2cc0c8f6376c3cbe565 ("de6*/dl2k/sundance: Move the D-Link drivers")
Tested-on: D-Link DGE-550T Rev-A3
Signed-off-by: Yeounsu Moon <redacted>
---
Changelog:
v1: https://lore.kernel.org/netdev/20250821114254.3384-1-yyyynoom@gmail.com/
v2:
- Change subject `net-next` to `net`.
- Add `Fixes:` tag.
---
 drivers/net/ethernet/dlink/dl2k.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/dlink/dl2k.c b/drivers/net/ethernet/dlink/dl2k.c
index cc60ee454bf9..6bbf6e5584e5 100644
--- a/drivers/net/ethernet/dlink/dl2k.c
+++ b/drivers/net/ethernet/dlink/dl2k.c

@@ -1099,7 +1099,7 @@ get_stats (struct net_device *dev)
 	dev->stats.rx_bytes += dr32(OctetRcvOk);
 	dev->stats.tx_bytes += dr32(OctetXmtOk);
 
-	dev->stats.multicast = dr32(McstFramesRcvdOk);
+	dev->stats.multicast += dr32(McstFramesRcvdOk);
 	dev->stats.collisions += dr32(SingleColFrames)
 			     +  dr32(MultiColFrames);
 

-- 
2.50.1

On Fri, Aug 22, 2025 at 09:02:46PM +0900, Yeounsu Moon wrote:

`McstFramesRcvdOk` counts the number of received multicast packets, and
it reports the value correctly.

However, reading `McstFramesRcvdOk` clears the register to zero. As a
result, the driver was reporting only the packets since the last read,
instead of the accumulated total.

Fix this by updating the multicast statistics accumulatively instaed of
instantaneously.

Fixes: 3401299a1b9e747cbf7de2cc0c8f6376c3cbe565 ("de6*/dl2k/sundance: Move the D-Link drivers")

The hash for fixes tends to be shorter than that.

Fixes: 3401299a1b9e ("de6*/dl2k/sundance: Move the D-Link drivers")

If you add this to your .git/config

[pretty]
        fixes = Fixes: %h (\"%s\")

You can do

git log --pretty=fixes 3401299a1b9e747cbf7de2cc0c8f6376c3cbe565
Fixes: 3401299a1b9e ("de6*/dl2k/sundance: Move the D-Link drivers")

This problem actually goes back further:

git blame 3401299a1b9e~1 drivers/net/dl2k.c

shows it was broken in the first commit in git.

So the correct Fixes: tag is:

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")

    Andrew

---
pw-bot: cr

On Sat Aug 23, 2025 at 12:15 AM KST, Andrew Lunn wrote:

The hash for fixes tends to be shorter than that.

Fixes: 3401299a1b9e ("de6*/dl2k/sundance: Move the D-Link drivers")

If you add this to your .git/config

[pretty]
        fixes = Fixes: %h (\"%s\")

You can do

git log --pretty=fixes 3401299a1b9e747cbf7de2cc0c8f6376c3cbe565
Fixes: 3401299a1b9e ("de6*/dl2k/sundance: Move the D-Link drivers")

Thanks for pointing that out.

This problem actually goes back further:

git blame 3401299a1b9e~1 drivers/net/dl2k.c

shows it was broken in the first commit in git.

So the correct Fixes: tag is:

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")

Regarding the Fixes: tag, I have one question. You suggested
1da177e4c3f4 ("Linux-2.6.12-rc2"), which is indeed the first commit in
the current git history. However, the actual code change seems to go
back further, and I found it in the history.git repository.

In such cases, should the Fixes: tag refer to the first commit in the
mailine git tree, or to the actual commit in history.git where the bug
originated?

Regarding the Fixes: tag, I have one question. You suggested
1da177e4c3f4 ("Linux-2.6.12-rc2"), which is indeed the first commit in
the current git history. However, the actual code change seems to go
back further, and I found it in the history.git repository.

In such cases, should the Fixes: tag refer to the first commit in the
mailine git tree, or to the actual commit in history.git where the bug
originated?

Nobody except historians care about history.git. In practice, nobody
cares about 2.6 either. https://www.kernel.org/ shows that v5.4 is the
oldest supported kernel. But Linux-2.6.12-rc2 is a convenient
reference point, so that is what is used when it has always been
broken in the git era.

	Andrew