When device side MTU is larger than host side MTU, the packets
(typically rmnet packets) are split over multiple MHI transfers.
In that case, fragments must be re-aggregated to recover the packet
before forwarding to upper layer.
A fragmented packet result in -EOVERFLOW MHI transaction status for
each of its fragments, except the final one. Such transfer was
previously considered as error and fragments were simply dropped.
This change adds re-aggregation mechanism using skb chaining, via
skb frag_list.
A warning (once) is printed since this behavior usually comes from
a misconfiguration of the device (e.g. modem MTU).
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Link: https://lore.kernel.org/r/1612428002-12333-1-git-send-email-loic.poulain@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
c1fcda2bdf