On Tue, Apr 13, 2021 at 10:19:30AM +0300, Ivan Bornyakov wrote: > 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.
Indeed - it should be a logical and operation - there is light present _and_ the PHY recognises the signal. This is what the commit achieves, although (iirc) doesn't cater for the case where there is no SFP cage attached. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
