On 04/21/2017 04:24 PM, Icenowy Zheng wrote:
> From: Icenowy Zheng <icenowy@xxxxxxxx>
>
> Some RTL8211E chips have broken GbE function, which needs a hack to
> fix. It's said that this fix will affect the performance on not-buggy
> PHYs, so it should only be enabled on boards with the broken PHY.
> Currently only some Pine64+ boards are known to have this issue.
>
> This hack is said to disable RX relay for RTL8211E according to Realtek.
>
> Enable this hack when a certain device tree property is set.
>
> As this hack is not documented on the datasheet at all, it contains
> magic numbers, and could not be revealed. These magic numbers are
> received from Realtek via Pine64.
>
> Signed-off-by: Icenowy Zheng <icenowy@xxxxxxxx>
> ---
> drivers/net/phy/realtek.c | 36 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
> index d820d00addf6..880022160cd2 100644
> --- a/drivers/net/phy/realtek.c
> +++ b/drivers/net/phy/realtek.c
> @@ -13,6 +13,7 @@
> * option) any later version.
> *
> */
> +#include <linux/of.h>
> #include <linux/phy.h>
> #include <linux/module.h>
>
> @@ -26,6 +27,8 @@
> #define RTL8211_PAGE_SELECT 0x1f
>
> #define RTL8211E_INER_LINK_STATUS 0x400
> +#define RTL8211E_EXT_PAGE_SELECT 0x1e
> +#define RTL8211E_EXT_PAGE 0x7
>
> #define RTL8211F_INER_LINK_STATUS 0x0010
> #define RTL8211F_INSR 0x1d
> @@ -121,6 +124,38 @@ static int rtl8211f_config_init(struct phy_device *phydev)
> return 0;
> }
>
> +static int rtl8211e_config_init(struct phy_device *phydev)
> +{
> + struct device *dev = &phydev->mdio.dev;
> + struct device_node *of_node = dev->of_node;
> + int ret;
> +
> + ret = genphy_config_init(phydev);
> + if (ret < 0)
> + return ret;
> +
> + if (of_node &&
> + of_property_read_bool(of_node, "realtek,disable-rx-delay")) {
> + /* All these magic numbers are retrieved from Pine64, and
> + * they're said to be originated from Realtek.
> + *
> + * The datasheet of RTL8211E didn't cover this ext page.
> + *
> + * Select extension page 0xa4 here.
> + */
> + phy_write(phydev, RTL8211_PAGE_SELECT, RTL8211E_EXT_PAGE)
> + phy_write(phydev, RTL8211E_EXT_PAGE_SELECT, 0xa4);
> +
> + /* Write the magic number */
> + phy_write(phydev, 0x1c, 0xb591);
> +
> + /* Restore to default page 0 */
> + phy_write(phydev, RTL8211_PAGE_SELECT, 0);
> + }
The code itself is probably fine, but the way you are checking whether
the RX delay should be disabled is not. As mentioned in patch 2, using
the correct "phy-mode" property would translate in the proper
phydev->interface value here (presumably PHY_INTERFACE_MODE_RGMII_TXID)
is that you want here that would allow you to check whether the RX delay
should, or should not be disabled.
Thank you
--
Florian
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