On Fri, Jul 10, 2020 at 02:08:51PM +0200, Oleksij Rempel wrote:
> This patch support for cable test for the ksz886x switches and the
> ksz8081 PHY.
>
> The patch was tested on a KSZ8873RLL switch with following results:
>
> - port 1:
> - cannot detect any distance
> - provides inverted values
> (Errata: DS80000830A: "LinkMD does not work on Port 1",
>
> http://ww1.microchip.com/downloads/en/DeviceDoc/KSZ8873-Errata-DS80000830A.pdf)
> - Reports "short" on open or ok.
> - Reports "ok" on short.
>
> - port 2:
> - can detect distance
> - can detect open on each wire of pair A (wire 1 and 2)
> - can detect open only on one wire of pair B (only wire 3)
> - can detect short between wires of a pair (wires 1 + 2 or 3 + 6)
> - short between pairs is detected as open.
> For example short between wires 2 + 3 is detected as open.
>
> In order to work around the errata for port 1, the ksz8795 switch driver
> should be extended to provide proper device tree support for the related
> PHY nodes. So we can set a DT property to mark the port 1 as affected by
> the errata.
Hi Oleksij
Do the PHY register read/writes pass through the DSA driver for the
8873? I was wondering if the switch could intercept reads/writes on
port1 for KSZ8081_LMD and return EOPNOTSUPP? That would be a more
robust solution than DT properties, which are going to get forgotten.
Andrew
