IFF_DRV_OACTIVE to note resource shortage to upper stack.
- Don't count number of mbuf chains. Default 32 DMA segments for a
frame is enough for most cases. If bus_dmamap_mbuf_sg fails use
m_collapse(9) to collapse the mbuf chain instead of relying on
expensive m_defrag(9).
- Move bpf handling to fxp_start_body() which is supposed to be
more appropriate place.
- Always arm watchdog timer whenever a new Tx request is made.
Previously fxp(4) used to arm watchdog timer only when
FXP_CXINT_THRESH-th Tx request is made. Because fxp(4) does not
rely on Tx interrupt to reclaim transmitted mbufs it's better to
arm watchdog timer to detect potential lockups.
- Add more aggresive Tx buffer reclaiming in fxp_start_body to make
room for new Tx requests. Since fxp(4) does not request Tx
completion interrupt for every frames it's necessary to clean
TXCBs in advance to saturate link.
- Make fxp(4) try to start more packets transmitting regardless of
interrupt type in fxp_intr_body.
4e53f83744