On Mon, Apr 12, 2021 at 06:28:33PM +0200, Pali Rohár wrote:
From: Russell King rmk+kernel@armlinux.org.uk
[ Upstream commit 624407d2cf14ff58e53bf4b2af9595c4f21d606e ]
The SFP MSA defines two option bits in byte 65 to indicate how the Rx_LOS signal on SFP pin 8 behaves:
bit 2 - Loss of Signal implemented, signal inverted from standard definition in SFP MSA (often called "Signal Detect"). bit 1 - Loss of Signal implemented, signal as defined in SFP MSA (often called "Rx_LOS").
Clearly, setting both bits results in a meaningless situation: it would mean that LOS is implemented in both the normal sense (1 = signal loss) and inverted sense (0 = signal loss).
Unfortunately, there are modules out there which set both bits, which will be initially interpret as "inverted" sense, and then, if the LOS signal changes state, we will toggle between LINK_UP and WAIT_LOS states.
Change our LOS handling to give well defined behaviour: only interpret these bits as meaningful if exactly one is set, otherwise treat it as if LOS is not implemented.
Signed-off-by: Russell King rmk+kernel@armlinux.org.uk Reviewed-by: Andrew Lunn andrew@lunn.ch Link: https://lore.kernel.org/r/E1kyYQa-0004iR-CU@rmk-PC.armlinux.org.uk Signed-off-by: Jakub Kicinski kuba@kernel.org
Please apply this commit to all stable releases where was already backported commit f0b4f847673299577c29b71d3f3acd3c313d81b7 ("net: sfp: add mode quirk for GPON module Ubiquiti U-Fiber Instant") as it depends on this commit. The Ubiquiti U-Fiber Instant SFP GPON module has set both LOS_NORMAL and LOS_INVERTED bits so without this commit it does not work. If I checked it correctly patch should go into 5.10 and 5.11 releases.
drivers/net/phy/sfp.c | 36 ++++++++++++++++++++++-------------- 1 file changed, 22 insertions(+), 14 deletions(-)
Now queued up, thanks.
greg k-h