Re: [PATCH net-next] net: dlink: count tx_dropped when dropping skb on link down
From: Yeounsu Moon <hidden>
Date: 2026-01-13 11:30:50
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On Tue Jan 6, 2026 at 10:44 PM KST, Andrew Lunn wrote:
On Tue, Jan 06, 2026 at 09:23:51PM +0900, Yeounsu Moon wrote:quoted
Increment tx_dropped when dropping the skb due to link down. Tested-on: D-Link DGE-550T Rev-A3 Signed-off-by: Yeounsu Moon <redacted> --- drivers/net/ethernet/dlink/dl2k.c | 1 + 1 file changed, 1 insertion(+)diff --git a/drivers/net/ethernet/dlink/dl2k.c b/drivers/net/ethernet/dlink/dl2k.c index 846d58c769ea..edc6cd64ac56 100644 --- a/drivers/net/ethernet/dlink/dl2k.c +++ b/drivers/net/ethernet/dlink/dl2k.c@@ -733,6 +733,7 @@ start_xmit (struct sk_buff *skb, struct net_device *dev) u64 tfc_vlan_tag = 0; if (np->link_status == 0) { /* Link Down */ + dev->stats.tx_dropped++;Do you see this being hit very often? It should be that as soon as you know the link is down, you tell the core, and it will stop calling start_xmit. If you see this counter being incremented a lot, it indicates there is a problem somewhere else. You might want to consider converting this driver to phylink. Andrew
Sorry for the late reply. I recently started my first job and have been
a bit busy settling in.
To answer your question: this path is hit extremely rarely. In practice,
I only observed it in rather extreme cases, such as forcibly
disconnecting the physical link (e.g. unplugging the Ethernet cable). I
have not seen it occurring during normal operation.
Given that, dropping the packet in this situation seems reasonable, so I
added a counter to make such cases visible. However, I am not entirely
sure whether this is the right direction, or whether this is just
masking a problem that should be handled elsewhere.
Do you think this should instead be addressed by improving how link-down
is propagted to the core, or would converting this driver to phylink
help avoid or improve this situation?
Yeounsu