Re: [PATCH net 2/2] net: phylink: Force retrigger in case of latched link-fail indicator
From: "Russell King (Oracle)" <linux@armlinux.org.uk>
Date: 2021-11-23 11:21:41
On Tue, Nov 23, 2021 at 12:51:54AM +0100, Marek Behún wrote:
On mv88e6xxx 1G/2.5G PCS, the SerDes register 4.2001.2 has the following
description:
This register bit indicates when link was lost since the last
read. For the current link status, read this register
back-to-back.
Thus to get current link state, we need to read the register twice.
But doing that in the link change interrupt handler would lead to
potentially ignoring link down events, which we really want to avoid.
Thus this needs to be solved in phylink's resolve, by retriggering
another resolve in the event when PCS reports link down and previous
link was up.
The wrong value is read when phylink requests change from sgmii to
2500base-x mode, and link won't come up. This fixes the bug.
Fixes: 9525ae83959b ("phylink: add phylink infrastructure")
Signed-off-by: Russell King (Oracle) <redacted>
Signed-off-by: Marek Behún <kabel@kernel.org>Same issue with this patch wrt authorship vs sign-off. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!