On Thu, Jul 16, 2020 at 02:57:24PM +0200, Helmut Grohne wrote:
> When doing "ip link set dev ... up" for a ksz9477 backed link,
> ksz9477_phy_setup is called and it calls phy_remove_link_mode to remove
> 1000baseT HDX. During phy_remove_link_mode, phy_advertise_supported is
> called. Doing so reverts any previous change to advertised link modes
> e.g. using a udevd .link file.
>
> phy_remove_link_mode is not meant to be used while opening a link and
> should be called during phy probe when the link is not yet available to
> userspace.
>
> Therefore move the phy_remove_link_mode calls into ksz9477_setup. This
> is called during dsa_switch_register and thus comes after
> ksz9477_switch_detect, which initializes dev->features.
>
> Remove phy_setup from ksz_dev_ops as no users remain.
>
> Link: https://lore.kernel.org/netdev/20200715192722.gd1256...@lunn.ch/
> Fixes: 42fc6a4c613019 ("net: dsa: microchip: prepare PHY for proper
> advertisement")
> Signed-off-by: Helmut Grohne <helmut.gro...@intenta.de>
> ---
> drivers/net/dsa/microchip/ksz9477.c | 31 ++++++++++----------------
> drivers/net/dsa/microchip/ksz_common.c | 2 --
> drivers/net/dsa/microchip/ksz_common.h | 2 --
> 3 files changed, 12 insertions(+), 23 deletions(-)
>
> changes since v1:
> * Don't change phy_remove_link_mode. Instead, call it at the right
> time. Thanks to Andrew Lunn for the detailed explanation.
>
> Helmut
Hi Helmut
This change looks better.
However, i'm having trouble understanding how PHYs actually work in
this driver.
We have:
struct ksz_port {
u16 member;
u16 vid_member;
int stp_state;
struct phy_device phydev;
with an instance of this structure per port of the switch.
And it is this phydev which you are manipulating.
> + for (i = 0; i < dev->phy_port_cnt; ++i) {
> + /* The MAC actually cannot run in 1000 half-duplex mode. */
> + phy_remove_link_mode(&dev->ports[i].phydev,
> + ETHTOOL_LINK_MODE_1000baseT_Half_BIT);
> +
> + /* PHY does not support gigabit. */
> + if (!(dev->features & GBIT_SUPPORT))
> + phy_remove_link_mode(&dev->ports[i].phydev,
> +
> ETHTOOL_LINK_MODE_1000baseT_Full_BIT);
> + }
> +
> return 0;
But how is this phydev associated with the netdev? I don't see how
phylink_connect_phy() is called using this phydev structure?
Andrew
