net: phylink: add support for polling MAC PCS
Some MAC PCS blocks are unable to provide interrupts when their status
changes. As we already have support in phylink for polling status, use
this to provide a hook for MACs to enable polling mode.
The patch idea was picked up from Russell King's suggestion on the macb
phylink patch thread here [0] but the implementation was changed.
Instead of introducing a new phylink_start_poll() function, which would
make the implementation cumbersome for common PHYLINK implementations
for multiple types of devices, like DSA, just add a boolean property to
the phylink_config structure, which is just as backwards-compatible.
https://lkml.org/lkml/2019/12/16/603
Suggested-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/networking/sfp-phylink.rst b/Documentation/networking/sfp-phylink.rst
index a5e00a1..d753a30 100644
--- a/Documentation/networking/sfp-phylink.rst
+++ b/Documentation/networking/sfp-phylink.rst
@@ -251,7 +251,8 @@
phylink_mac_change(priv->phylink, link_is_up);
where ``link_is_up`` is true if the link is currently up or false
- otherwise.
+ otherwise. If a MAC is unable to provide these interrupts, then
+ it should set ``priv->phylink_config.pcs_poll = true;`` in step 9.
11. Verify that the driver does not call::