RE: [EXT] [PATCH] mwifiex: set needed_headroom, not hard_header_len

Hi Brian,

quoted

quoted

hard_header_len provides limitations for things like AF_PACKET, such
that we don't allow transmitting packets smaller than this.

OK; However, are we not supposed to mention hard_header_len also?

No, my understanding is that we do not need to bother with
hard_header_len ourselves -- ether_setup() establishes the appropriate
L2 header parameters. I think that's covered a little better below.

OK. I got you.

quoted

quoted

This is the essentially the same bug (and fix) that brcmfmac had,
fixed in commit cb39288fd6bb ("brcmfmac: use ndev-

needed_headroom

quoted

to reserve additional header space").

OK; I read this commit:

"... According to definition of LL_RESERVED_SPACE() and hard_header_len,

we should use hard_header_len to reserve for L2 header, like ethernet
header(ETH_HLEN) in our case and use needed_headroom for the additional
headroom needed by hardware..."

Yeah, that's probably a little more verbose and accurate description, which is
partly why I referred to that commit :)

quoted

So, does it mean, hard_header_len is already considered by upper layer?

Right, it's set by ether_setup().

Yes, Thanks.

Acked-by: Ganapathi Bhat <redacted>

Regards,
Ganapathi