On Thu, Aug 18, 2022 at 11:00:54AM +0800, wei.fang@xxxxxxx wrote: > From: Wei Fang <wei.fang@xxxxxxx> > > When the cable is unplugged, the Atheros AR803x PHYs will enter > hibernation mode after about 10 seconds if the hibernation mode > is enabled and will not provide any clock to the MAC. But for > some MACs, this feature might cause unexpected issues due to the > logic of MACs. > Taking SYNP MAC (stmmac) as an example, if the cable is unplugged > and the "eth0" interface is down, the AR803x PHY will enter > hibernation mode. Then perform the "ifconfig eth0 up" operation, > the stmmac can't be able to complete the software reset operation > and fail to init it's own DMA. Therefore, the "eth0" interface is > failed to ifconfig up. Why does it cause this issue? The truth is > that the software reset operation of the stmmac is designed to > depend on the RX_CLK of PHY. > So, this patch offers an option for the user to determine whether > to disable the hibernation mode of AR803x PHYs. > > Signed-off-by: Wei Fang <wei.fang@xxxxxxx> Reviewed-by: Andrew Lunn <andrew@xxxxxxx> Andrew