DMA_CHAN_TX_END_ADDR
reg_space[DMA_CHAN_TX_END_ADDR(default_addrs, channel) / 4] =
readl(ioaddr + DMA_CHAN_TX_END_ADDR(dwmac4_addrs, channel));
writel(tail_ptr, ioaddr + DMA_CHAN_TX_END_ADDR(dwmac4_addrs, chan));