U3D_COMMON_USB_INTR
mtu3_writel(mbase, U3D_COMMON_USB_INTR, ~0x0);
u2comm = mtu3_readl(mbase, U3D_COMMON_USB_INTR);
mtu3_writel(mbase, U3D_COMMON_USB_INTR, u2comm); /* W1C */