Re: [PATCH net-next v5 2/7] net: stmmac: Add dedicated XPCS cleanup method

From: Serge Semin
Date: Thu May 02 2024 - 18:35:11 EST


Hi Romain

On Tue, Apr 30, 2024 at 09:29:42AM +0200, Romain Gantois wrote:
> From: Serge Semin <fancer.lancer@xxxxxxxxx>
>
> Currently the XPCS handler destruction is performed in the
> stmmac_mdio_unregister() method. It doesn't look good because the handler
> isn't originally created in the corresponding protagonist
> stmmac_mdio_unregister(), but in the stmmac_xpcs_setup() function. In
> order to have more coherent MDIO and XPCS setup/cleanup procedures,
> let's move the DW XPCS destruction to the dedicated stmmac_pcs_clean()
> method.
>
> This method will also be used to cleanup PCS hardware using the
> pcs_exit() callback that will be introduced to stmmac in a subsequent
> patch.
>
> Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx>
> Co-developed-by: Romain Gantois <romain.gantois@xxxxxxxxxxx>
> Signed-off-by: Romain Gantois <romain.gantois@xxxxxxxxxxx>
> ---
> drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 +
> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 +++++-
> drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 12 +++++++++---
> 3 files changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> index dddcaa9220cc3..7e0d727ed795b 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> @@ -361,6 +361,7 @@ int stmmac_mdio_unregister(struct net_device *ndev);
> int stmmac_mdio_register(struct net_device *ndev);
> int stmmac_mdio_reset(struct mii_bus *mii);
> int stmmac_xpcs_setup(struct mii_bus *mii);
> +void stmmac_pcs_clean(struct stmmac_priv *priv);
> void stmmac_set_ethtool_ops(struct net_device *netdev);
>
> int stmmac_init_tstamp_counter(struct stmmac_priv *priv, u32 systime_flags);
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 59bf83904b62d..2a55c5d07f6b8 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -7789,8 +7789,9 @@ int stmmac_dvr_probe(struct device *device,
>
> error_netdev_register:
> phylink_destroy(priv->phylink);
> -error_xpcs_setup:
> error_phy_setup:
> + stmmac_pcs_clean(priv);
> +error_xpcs_setup:
> if (priv->hw->pcs != STMMAC_PCS_TBI &&
> priv->hw->pcs != STMMAC_PCS_RTBI)
> stmmac_mdio_unregister(ndev);
> @@ -7832,6 +7833,9 @@ void stmmac_dvr_remove(struct device *dev)
> if (priv->plat->stmmac_rst)
> reset_control_assert(priv->plat->stmmac_rst);
> reset_control_assert(priv->plat->stmmac_ahb_rst);
> +
> + stmmac_pcs_clean(priv);
> +
> if (priv->hw->pcs != STMMAC_PCS_TBI &&
> priv->hw->pcs != STMMAC_PCS_RTBI)
> stmmac_mdio_unregister(ndev);
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> index 0542cfd1817e6..508bd39cbe2b3 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> @@ -523,6 +523,15 @@ int stmmac_xpcs_setup(struct mii_bus *bus)
> return 0;
> }
>

> +void stmmac_pcs_clean(struct stmmac_priv *priv)

Ideally it would have been great to have the entire driver fixed to
accept the stmmac_priv pointer as the functions argument. But this
would be too tiresome. Anyway seeing the PCS-setup protagonist method
has the net_device pointer passed I would implement the same prototype
for the antagonist even though it would require an additional local
variable. That will make the MDIO and PCS local interface-functions
looking alike and as if unified. That is the reason of why I made
stmmac_xpcs_clean() accepting the net_device pointer.

Alternatively both stmmac_pcs_setup() and stmmac_pcs_clean() could be
converted to just accepting a pointer to the stmmac_priv instance.

-Serge(y)

> +{
> + if (!priv->hw->xpcs)
> + return;
> +
> + xpcs_destroy(priv->hw->xpcs);
> + priv->hw->xpcs = NULL;
> +}
> +
> /**
> * stmmac_mdio_register
> * @ndev: net device structure
> @@ -679,9 +688,6 @@ int stmmac_mdio_unregister(struct net_device *ndev)
> if (!priv->mii)
> return 0;
>
> - if (priv->hw->xpcs)
> - xpcs_destroy(priv->hw->xpcs);
> -
> mdiobus_unregister(priv->mii);
> priv->mii->priv = NULL;
> mdiobus_free(priv->mii);
>
> --
> 2.44.0
>