do not drop force feedback packets

[paroj]

while the URB ffff88020d047d80 submitted while active issue is fixed in master, FFB packets might still be dropped.
Consider this patch for SteamOS.

However I first need a way to reproduce this. Using fftest is not enough to triggering the error.

[Hietamaki]

Related? http://steamcommunity.com/app/233130/discussions/0/611702631210587760/#c611702631214382829

[paroj]

yes, related. but the linked patch is a better solution.

[paroj]

according to dtor one should not use a queue. makes sense.
http://www.spinics.net/lists/linux-input/msg40708.html

[paroj]

and this is a test for reproducing the race:

while true; do
        for i in $(seq 0 5); do
                echo $i > /sys/class/leds/xpad0/subsystem/xpad0/brightness
        done
done

[paroj]

re-submitting logic is now in master: 906c1f1.
verified that LED commands get correctly re-submitted.
Still need a test for FF commands. Otherwise done.

[paroj]

actually this particular problem is fixed. the next one is in #10