On Wed, 24 Sep 2025 19:50:55 +0200, Michal Pecio wrote:

Do you happen to remember what was the reason for padding all TX frames
to at least 60 bytes?

This was apparently added in version "v0.5.0 (2002/03/28)".

I'm yet to test the exact effect of this hack (will the HW really send
frames with trailing garbage?) and what happens if it's removed (maybe
nothing bad? or was there a HW bug?), but this part caught my attention
because I think nowadays some people could consider it "information
leak" ;) And it looks like a waste of bandwidth at least.

Sorry, stupid question, such frames are illegal.

That being said, I see that other drivers pad them with zeros or
other fixed pattern ('skb_padto(skb, ETH_ZLEN)' seems to be common)
rather than just DMA beyond the specified length.