Re: [RFC PATCH net-next v3 13/20] net: dsa: qca8k: make rgmii delay configurable

Andrew Lunn
2021-05-05T01:00:52Z

On Wed, May 05, 2021 at 12:29:07AM +0200, Ansuel Smith wrote:
> The legacy qsdk code used a different delay instead of the max value.
> Qsdk use 1 ps for rx and 2 ps for tx. Make these values configurable
> using the standard rx/tx-internal-delay-ps ethernet binding and apply
> qsdk values by default. The connected gmac doesn't add any delay so no
> additional delay is added to tx/rx.
>
> Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> ---
> drivers/net/dsa/qca8k.c | 51 +++++++++++++++++++++++++++++++++++++++--
> drivers/net/dsa/qca8k.h | 11 +++++----
> 2 files changed, 55 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
> index 22334d416f53..cb9b44769e92 100644
> --- a/drivers/net/dsa/qca8k.c
> +++ b/drivers/net/dsa/qca8k.c
> @@ -779,6 +779,47 @@ qca8k_setup_mdio_bus(struct qca8k_priv *priv)
> return 0;
> }
>
> +static int
> +qca8k_setup_of_rgmii_delay(struct qca8k_priv *priv)
> +{
> + struct device_node *ports, *port;
> + u32 val;
> +
> + ports = of_get_child_by_name(priv->dev->of_node, "ports");
> + if (!ports)
> + return -EINVAL;
> +
> + /* Assume only one port with rgmii-id mode */
> + for_each_available_child_of_node(ports, port) {

Are delays global? Or per port? They really should be per port. If it
is global, one value that applies to all ports, i would not use
it. Have the PHY apply the delay, not the MAC.

Andrew