Re: [PATCH] drivers/net/wan/lapbether: Use needed_headroom instead of hard_header_len

From: Xie He
Date: Mon Jul 27 2020 - 15:41:30 EST

Hi Cong Wang,

I'm wishing to change a driver from using "hard_header_len" to using
"needed_headroom" to declare its needed headroom. I submitted a patch
and it is decided it needs to be reviewed. I see you participated in
"hard_header_len vs needed_headroom" discussions in the past. Can you
help me review this patch? Thanks!

The patch is at:

In my understanding, hard_header_len should be the length of the header
created by dev_hard_header. Any additional headroom needed should be
declared in needed_headroom instead of hard_header_len. I came to this
conclusion by examining the logic of net/packet/af_packet.c:packet_snd.

What do you think?