Re: [PATCH 06/11] net: ethernet: mtk-eth-mac: new driver

[Joe Perches]

On Wed, 2020-05-06 at 22:16 +0300, Leon Romanovsky wrote:
> On Tue, May 5, 2020 at 5:03 PM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
> > From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> > 
> > This adds the driver for the MediaTek Ethernet MAC used on the MT8* SoC
> > family. For now we only support full-duplex.
[]
> > diff --git a/drivers/net/ethernet/mediatek/mtk_eth_mac.c b/drivers/net/ethernet/mediatek/mtk_eth_mac.c
[]
> > +struct mtk_mac_priv {
> > +       struct regmap *regs;
> > +       struct regmap *pericfg;
> > +
> > +       struct clk_bulk_data clks[MTK_MAC_NCLKS];
> > +
> > +       void *ring_base;
> > +       struct mtk_mac_ring_desc *descs_base;
> > +       dma_addr_t dma_addr;
> > +       struct mtk_mac_ring tx_ring;
> > +       struct mtk_mac_ring rx_ring;
> > +       struct work_struct tx_work;
> > +
> > +       struct mii_bus *mii;
> > +       struct napi_struct napi;
> > +
> > +       struct device_node *phy_node;
> > +       phy_interface_t phy_intf;
> > +       struct phy_device *phydev;
> > +       unsigned int link;
> > +       int speed;
> > +       int duplex;
> > +
> > +       /* Protects against concurrent descriptor access. */
> > +       spinlock_t lock;
> > +       unsigned long lock_flags;
> > +
> > +       struct rtnl_link_stats64 stats;
> > +};
> > +
> > +static struct net_device *mtk_mac_get_netdev(struct mtk_mac_priv *priv)
> > +{
> > +       char *ptr = (char *)priv;
> > +
> > +       return (struct net_device *)(ptr - ALIGN(sizeof(struct net_device),
> > +                                                NETDEV_ALIGN));
> > +}

This code looks ugly/fragile.
Why not store the struct net_device * in struct mtk_mac_priv ?