Hi Brian, > > > 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. > > > > This is the essentially the same bug (and fix) that brcmfmac had, > > > fixed in commit cb39288fd6bb ("brcmfmac: use ndev- > >needed_headroom > > > 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 :) > > > 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 <ganapathi.gbhat@xxxxxxx> Regards, Ganapathi