linux-wandboard

r8152: support runtime suspend

Support runtime suspend for RTL8152 and RTL8153.

Move tx_bottom() from tasklet to delayed_work. That avoids to
transmit tx packets after calling autosuspend.

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>