Does anyone use the libertas (marvell 8686) SDIO card in the beagleboard?

Dear all:
    I boot the BeagleBoard from NAND, and the libertas SDIO card
(Gemtek GM9601) is inserted in the MMC slot. Now I have a trouble is
that the transmission speed is very slow. I use the "iperf to evaluate
the speed of UDP transmission, and the result is only about 1.5 Mb/
s.When I traced the libertas source code, I found after the main
thread send data to SDIO, it must wait for about 8~10 msec to receive
the host_to_card_done event and then the main thread can continue to
send data through SDIO. I tried many different marvell firmwares, and
the situation is the same.

    Now I am checking whether the SDIO use the DMA.

PS: The iperf command I used is "iperf -c ServerAddress -u -b 54M -t
10"

Just curious, where did you get the sd8686.bin and sd8686_helper.bin
file from?
I tried the ones from the Marvell website, it didn't work out. Btw,
where is it supposed to be place? (/lib/firmware/mrvl)?

No persoanl experience with this but have a look at http://elinux.org/Libertas_SDIO