Re: [RFC PATCH v1 2/9] net: dsa: microchip: ksz8795: add phylink support

Vladimir Oltean
2021-05-06T12:14:12Z

Hi Oleksij,

On Wed, May 05, 2021 at 11:20:18AM +0200, Oleksij Rempel wrote:
> From: Michael Grzeschik <m.grzeschik@pengutronix.de>
>
> This patch adds the phylink support to the ksz8795 driver, since
> phylib is obsolete for dsa drivers.
>
> Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
> drivers/net/dsa/microchip/ksz8795.c | 73 +++++++++++++++++++++++++++++
> 1 file changed, 73 insertions(+)
>
> diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
> index 4ca352fbe81c..0ddaf2547f18 100644
> --- a/drivers/net/dsa/microchip/ksz8795.c
> +++ b/drivers/net/dsa/microchip/ksz8795.c
> @@ -18,6 +18,7 @@
> #include <linux/micrel_phy.h>
> #include <net/dsa.h>
> #include <net/switchdev.h>
> +#include <linux/phylink.h>
>
> #include "ksz_common.h"
> #include "ksz8795_reg.h"
> @@ -1420,11 +1421,83 @@ static int ksz8_setup(struct dsa_switch *ds)
> return 0;
> }
>
> +static int ksz_get_state(struct dsa_switch *ds, int port,
> + struct phylink_link_state *state)
> +{
> + struct ksz_device *dev = ds->priv;
> + struct ksz8 *ksz8 = dev->priv;
> + const u8 *regs = ksz8->regs;
> + u8 speed, link;
> +
> + ksz_pread8(dev, port, regs[P_LINK_STATUS], &link);
> + ksz_pread8(dev, port, regs[P_SPEED_STATUS], &speed);
> +
> + state->link = !!(link & PORT_STAT_LINK_GOOD);
> + if (state->link) {
> + state->speed =
> + (speed & PORT_STAT_SPEED_100MBIT) ? SPEED_100 : SPEED_10;
> + state->duplex =
> + (speed & PORT_STAT_FULL_DUPLEX) ? DUPLEX_FULL : DUPLEX_HALF;
> + }
> +
> + return 0;
> +}
> +
> +static void ksz_validate(struct dsa_switch *ds, int port,
> + unsigned long *supported,
> + struct phylink_link_state *state)
> +{
> + __ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
> + struct ksz_device *dev = ds->priv;
> +
> + if (port == dev->cpu_port) {
> + if ((state->interface != PHY_INTERFACE_MODE_RMII) &&
> + (state->interface != PHY_INTERFACE_MODE_MII))
> + goto unsupported;
> + } else if (port > dev->port_cnt) {
> + bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
> + dev_err(ds->dev, "Unsupported port: %i\n", port);
> + return;
> + } else {
> + if (state->interface != PHY_INTERFACE_MODE_INTERNAL)
> + goto unsupported;
> + }
> +
> + /* Allow all the expected bits */
> + phylink_set_port_modes(mask);
> + phylink_set(mask, Autoneg);
> +
> + phylink_set(mask, Pause);
> + /* Silicon Errata Sheet (DS80000830A): Asym_Pause limit to port 2 */
> + if (port || !ksz_is_ksz88x3(dev))
> + phylink_set(mask, Asym_Pause);
> +
> + /* 10M and 100M are only supported */
> + phylink_set(mask, 10baseT_Half);
> + phylink_set(mask, 10baseT_Full);
> + phylink_set(mask, 100baseT_Half);
> + phylink_set(mask, 100baseT_Full);
> +
> + bitmap_and(supported, supported, mask,
> + __ETHTOOL_LINK_MODE_MASK_NBITS);
> + bitmap_and(state->advertising, state->advertising, mask,
> + __ETHTOOL_LINK_MODE_MASK_NBITS);
> +
> + return;
> +
> +unsupported:
> + bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
> + dev_err(ds->dev, "Unsupported interface: %d, port: %d\n",
> + state->interface, port);
> +}
> +
> static const struct dsa_switch_ops ksz8_switch_ops = {
> .get_tag_protocol = ksz8_get_tag_protocol,
> .setup = ksz8_setup,
> .phy_read = ksz_phy_read16,
> .phy_write = ksz_phy_write16,
> + .phylink_validate = ksz_validate,
> + .phylink_mac_link_state = ksz_get_state,
> .phylink_mac_link_down = ksz_mac_link_down,
> .port_enable = ksz_enable_port,
> .get_strings = ksz8_get_strings,
> --
> 2.29.2
>

I've asked Prasanna about this too, but for one reason or another I am
still not edified. Is this change a compliance thing, or do you actually
gain anything at all from phylink?
https://patchwork.kernel.org/project/netdevbpf/patch/20210422094257.1641396-6-prasanna.vengateshan@microchip.com/
What made you submit the patch?