Re: [PATCH net-next v3] net: phy: micrel: add phy-mode support for the KSZ9031 PHY

[Grygorii Strashko <grygorii.strashko@ti.com>]

On 22/04/2020 10:21, Oleksij Rempel wrote:
> Add support for following phy-modes: rgmii, rgmii-id, rgmii-txid, rgmii-rxid.
> 
> This PHY has an internal RX delay of 1.2ns and no delay for TX.
> 
> The pad skew registers allow to set the total TX delay to max 1.38ns and
> the total RX delay to max of 2.58ns (configurable 1.38ns + build in
> 1.2ns) and a minimal delay of 0ns.
> 
> According to the RGMII v1.3 specification the delay provided by PCB traces
> should be between 1.5ns and 2.0ns. The RGMII v2.0 allows to provide this
> delay by MAC or PHY. So, we configure this PHY to the best values we can
> get by this HW: TX delay to 1.38ns (max supported value) and RX delay to
> 1.80ns (best calculated delay)
> 
> The phy-modes can still be fine tuned/overwritten by *-skew-ps
> device tree properties described in:
> Documentation/devicetree/bindings/net/micrel-ksz90x1.txt
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
> changes v3:
> - change delay on RX line to 1.80ns
> - add warning if *-skew-ps properties are used together with not rgmii
>    mode.
> 
> changes v2:
> - change RX_ID value from 0x1a to 0xa. The overflow bit was detected by
>    FIELD_PREP() build check.
>    Reported-by: kbuild test robot <lkp@intel.com>
> 
>   drivers/net/phy/micrel.c | 128 +++++++++++++++++++++++++++++++++++++--
>   1 file changed, 123 insertions(+), 5 deletions(-)
> 

This patch broke networking on at least 5 TI boards:
am572x-idk
am571x-idk
am43xx-hsevm
am43xx-gpevm
am437x-idk

am57xx I can fix.

am437x need to investigate.

-- 
Best regards,
grygorii