On Tue, Apr 13, 2021 at 01:40:32AM +0200, Andrew Lunn wrote: > On Mon, Apr 12, 2021 at 03:16:59PM +0300, Ivan Bornyakov wrote: > > Some SFP modules uses RX_LOS for link indication. In such cases link > > will be always up, even without cable connected. RX_LOS changes will > > trigger link_up()/link_down() upstream operations. Thus, check that SFP > > link is operational before actual read link status. > > Sorry, but this is not making much sense to me. > > LOS just indicates some sort of light is coming into the device. You > have no idea what sort of light. The transceiver might be able to > decode that light and get sync, it might not. It is important that > mv2222_read_status() returns the line side status. Has it been able to > achieve sync? That should be independent of LOS. Or are you saying the > transceiver is reporting sync, despite no light coming in? > > Andrew
Yes, with some SFP modules transceiver is reporting sync despite no light coming in. So, the idea is to check that link is somewhat operational before determing line-side status.
