Re: [PATCH v2 4/4] drivers: net: Add APM X-Gene SoC ethernet driver support.

Hi,

Please find my response inline.

On Mon, Apr 14, 2014 at 7:05 AM, Ben Dooks [off-list ref] wrote:

On 12/04/14 04:06, Iyappan Subramanian wrote:

quoted

This patch adds network driver for APM X-Gene SoC ethernet.

Signed-off-by: Iyappan Subramanian <redacted>
Signed-off-by: Ravi Patel <redacted>

[snip]

quoted

+{
+       struct xgene_enet_pdata *pdata = netdev_priv(ndev);
+       struct phy_device *phydev;
+       unsigned char phy_id[MII_BUS_ID_SIZE+3];
+       int ret = 0;
+
+       phydev = phy_find_first(pdata->mdio_bus);
+       if (!phydev) {
+               netdev_info(ndev, "no PHY found\n");
+               ret = -1;
+               goto out;
+       }
+
+       /* attach the mac to the phy */
+       snprintf(phy_id, sizeof(phy_id), PHY_ID_FMT, pdata->mdio_bus->id,
+                pdata->phy_addr);
+       phydev = phy_connect(ndev, phy_id,
+                            &xgene_enet_mdio_link_change,
pdata->phy_mode);
+       if (IS_ERR(phydev)) {
+               netdev_err(ndev, "Could not attach to PHY\n");
+               ret = PTR_ERR(phydev);
+               phydev = NULL;
+               goto out;
+       }
+

You should be using of_phy_connect or similar so that the
necessary PHY<>OF data is properly initialised

I will use of_phy_connect function to connect to PHY.

quoted

+       netdev_info(ndev, "phy_id=0x%08x phy_drv=\"%s\"",
+                   phydev->phy_id, phydev->drv->name);
+out:
+       pdata->phy_link = 0;
+       pdata->phy_speed = 0;
+       pdata->phy_dev = phydev;
+
+       return ret;
+}
+

[snip]

quoted

+struct xgene_enet_desc {
+       u64 m0;
+       u64 m1;
+       u64 m2;
+       u64 m3;
+};
+
+struct xgene_enet_desc16 {
+       u64 m0;
+       u64 m1;
+};
+
+static inline void xgene_enet_cpu_to_le64(struct xgene_enet_desc *desc,
+                                         int count)
+{
+#ifdef CONFIG_CPU_BIG_ENDIAN
+       int i;
+
+       for (i = 0; i < count; i++)
+               ((u64 *)desc)[i] = cpu_to_le64(((u64 *)desc)[i]);
+#endif
+}
+
+static inline void xgene_enet_le64_to_cpu(struct xgene_enet_desc *desc,
+                                         int count)
+{
+#ifdef CONFIG_CPU_BIG_ENDIAN
+       int i;
+
+       for (i = 0; i < count; i++)
+               ((u64 *)desc)[i] = le64_to_cpu(((u64 *)desc)[i]);
+#endif
+}
+
+static inline void xgene_enet_desc16_to_le64(struct xgene_enet_desc
*desc)
+{
+#ifdef CONFIG_CPU_BIG_ENDIAN
+       ((u64 *)desc)[1] = cpu_to_le64(((u64 *)desc)[1]);
+#endif
+}
+
+static inline void xgene_enet_le64_to_desc16(struct xgene_enet_desc
*desc)
+{
+#ifdef CONFIG_CPU_BIG_ENDIAN
+       ((u64 *)desc)[1] = le64_to_cpu(((u64 *)desc)[1]);
+#endif
+}

With this do you not risk confusing the hardware by swapping the
format of the descriptors?

Why not use xxx_to_cpu() and cpu_to_xxx() functions when reading or
writing the descriptors? It would also remove a lot of the #ifdef in
this code.

Our hardware expects descriptor in the little endian format.  I will remove the
#ifdef.

--
Ben Dooks                               http://www.codethink.co.uk/
Senior Engineer                         Codethink - Providing Genius

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