[PATCH v4 06/22] net: phy: xilinx: Be compatible with live OF tree

[Michal Simek]

Hi Bin,

ne 14. 3. 2021 v 13:17 odesílatel Bin Meng <bmeng.cn at gmail.com> napsal:
>
> Following the same updates that were done to the fixed phy driver,
> use ofnode_ APIs instead of fdt_ APIs so that the Xilinx PHY driver
> can support live DT.
>
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>
> ---
>
> (no changes since v2)
>
> Changes in v2:
> - move device tree parsing from xilinxgmiitorgmii_probe() to
>   xilinxgmiitorgmii_config() and use OF APIs
>
>  drivers/net/phy/phy.c               | 23 +++++------
>  drivers/net/phy/xilinx_gmii2rgmii.c | 61 ++++++++++++++---------------
>  2 files changed, 40 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> index eae40cc0d6..d464379121 100644
> --- a/drivers/net/phy/phy.c
> +++ b/drivers/net/phy/phy.c
> @@ -953,23 +953,20 @@ static struct phy_device *phy_connect_gmii2rgmii(struct mii_dev *bus,
>  #endif
>  {
>         struct phy_device *phydev = NULL;
> -       int sn = dev_of_offset(dev);
> -       int off;
> -
> -       while (sn > 0) {
> -               off = fdt_node_offset_by_compatible(gd->fdt_blob, sn,
> -                                                   "xlnx,gmii-to-rgmii-1.0");
> -               if (off > 0) {
> -                       phydev = phy_device_create(bus, off,
> +       ofnode node = dev_ofnode(dev);
> +
> +       while (ofnode_valid(node)) {
> +               node = ofnode_by_compatible(node, "xlnx,gmii-to-rgmii-1.0");
> +               if (ofnode_valid(node)) {
> +                       phydev = phy_device_create(bus, 0,
>                                                    PHY_GMII2RGMII_ID, false,
>                                                    interface);
> +                       if (phydev)
> +                               phydev->node = node;
>                         break;
>                 }
> -               if (off == -FDT_ERR_NOTFOUND)
> -                       sn = fdt_first_subnode(gd->fdt_blob, sn);
> -               else
> -                       printf("%s: Error finding compat string:%d\n",
> -                              __func__, off);
> +
> +               node = ofnode_first_subnode(node);
>         }
>
>         return phydev;
> diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c b/drivers/net/phy/xilinx_gmii2rgmii.c
> index 74105c0b7d..635c0570ef 100644
> --- a/drivers/net/phy/xilinx_gmii2rgmii.c
> +++ b/drivers/net/phy/xilinx_gmii2rgmii.c
> @@ -18,9 +18,38 @@ DECLARE_GLOBAL_DATA_PTR;
>
>  static int xilinxgmiitorgmii_config(struct phy_device *phydev)
>  {
> -       struct phy_device *ext_phydev = phydev->priv;
> +       ofnode node = phy_get_ofnode(phydev);
> +       struct phy_device *ext_phydev;
> +       struct ofnode_phandle_args phandle;
> +       int ext_phyaddr = -1;
> +       int ret;
>
>         debug("%s\n", __func__);
> +
> +       if (!ofnode_valid(node))
> +               return -EINVAL;
> +
> +       phydev->addr = ofnode_read_u32_default(node, "reg", -1);
> +       ret = ofnode_parse_phandle_with_args(node, "phy-handle",
> +                                            NULL, 0, 0, &phandle);
> +       if (ret)
> +               return ret;
> +
> +       ext_phyaddr = ofnode_read_u32_default(phandle.node, "reg", -1);
> +       ext_phydev = phy_find_by_mask(phydev->bus,
> +                                     1 << ext_phyaddr,
> +                                     PHY_INTERFACE_MODE_RGMII);
> +       if (!ext_phydev) {
> +               printf("%s, No external phy device found\n", __func__);
> +               return -EINVAL;
> +       }
> +
> +       ext_phydev->node = phandle.node;
> +       phydev->priv = ext_phydev;
> +
> +       debug("%s, gmii2rgmmi:0x%x, extphy:0x%x\n", __func__, phydev->addr,
> +             ext_phyaddr);
> +
>         if (ext_phydev->drv->config)
>                 ext_phydev->drv->config(ext_phydev);
>
> @@ -83,11 +112,6 @@ static int xilinxgmiitorgmii_startup(struct phy_device *phydev)
>
>  static int xilinxgmiitorgmii_probe(struct phy_device *phydev)
>  {
> -       int ofnode = phydev->addr;
> -       u32 phy_of_handle;
> -       int ext_phyaddr = -1;
> -       struct phy_device *ext_phydev;
> -
>         debug("%s\n", __func__);
>
>         if (phydev->interface != PHY_INTERFACE_MODE_GMII) {
> @@ -95,31 +119,6 @@ static int xilinxgmiitorgmii_probe(struct phy_device *phydev)
>                 return -EINVAL;
>         }
>
> -       /*
> -        * Read the phy address again as the one we read in ethernet driver
> -        * was overwritten for the purpose of storing the ofnode
> -        */
> -       phydev->addr = fdtdec_get_int(gd->fdt_blob, ofnode, "reg", -1);
> -       phy_of_handle = fdtdec_lookup_phandle(gd->fdt_blob, ofnode,
> -                                             "phy-handle");
> -       if (phy_of_handle > 0)
> -               ext_phyaddr = fdtdec_get_int(gd->fdt_blob,
> -                                            phy_of_handle,
> -                                            "reg", -1);
> -       ext_phydev = phy_find_by_mask(phydev->bus,
> -                                     1 << ext_phyaddr,
> -                                     PHY_INTERFACE_MODE_RGMII);
> -       if (!ext_phydev) {
> -               printf("%s, No external phy device found\n", __func__);
> -               return -EINVAL;
> -       }
> -
> -       ext_phydev->node = offset_to_ofnode(phy_of_handle);
> -       phydev->priv = ext_phydev;
> -
> -       debug("%s, gmii2rgmmi:0x%x, extphy:0x%x\n", __func__, phydev->addr,
> -             ext_phyaddr);
> -
>         phydev->flags |= PHY_FLAG_BROKEN_RESET;
>
>         return 0;
> --
> 2.25.1
>

This patch is breaking u-boot on ZynqMP. In phy_connect_gmii2rgmii you
get a valid node from dev_ofnode(dev)
and you enter the while loop because ofnode_valid(node) returns true.
ofnode_by_compatible() will fail because it is not normally
gmii-to-rgmii bridge and will go to ofnode_first_subnode() which
returns 0
which goes back to ofnode_valid() which pass again because 0 is valid
and it keeps going in this while loop.
This is with xilinx_zynqmp_virt_defconfig configuration with OF_LIVE
off but with OF_LIVE on behavior is the same.

It means that the while loop should be replaced by something more deterministic.
What about?
ofnode_for_each_subnode(node, dev_ofnode(dev)) {

Thanks,
Michal


-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Xilinx Microblaze
Maintainer of Linux kernel - Xilinx Zynq ARM and ZynqMP ARM64 SoCs
U-Boot custodian - Xilinx Microblaze/Zynq/ZynqMP/Versal SoCs