On Wed, May 22, 2019 at 06:43:23PM +0000, Trent Piepho wrote:
> The code was assuming the reset default of the delay control register
> was to have delay disabled. This is what the datasheet shows as the
> register's initial value. However, that's not actually true: the
> default is controlled by the PHY's pin strapping.
>
> If the interface mode is selected as RX or TX delay only, insure the
> other direction's delay is disabled.
>
> If the interface mode is just "rgmii", with neither TX or RX internal
> delay, one might expect that the driver should disable both delays. But
> this is not what the driver does. It leaves the setting at the PHY's
> strapping's default. And that default, for no pins with strapping
> resistors, is to have delay enabled and 2.00 ns.
>
> Rather than change this behavior, I've kept it the same and documented
> it. No delay will most likely not work and will break ethernet on any
> board using "rgmii" mode. If the board is strapped to have a delay and
> is configured to use "rgmii" mode a warning is generated that "rgmii-id"
> should have been used.
>
> Also validate the delay values and fail if they are not in range.
>
> Cc: Andrew Lunn <andrew@xxxxxxx>
> Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
> Cc: Heiner Kallweit <hkallweit1@xxxxxxxxx>
> Signed-off-by: Trent Piepho <tpiepho@xxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Andrew
