Re: [PATCH v2 3/4] net: phy: realtek: add disable RX internal delay mode

[icenowy]

å 2017-08-22 21:39ïAndrew Lunn åéï
> On Tue, Aug 22, 2017 at 12:03:59PM +0800, 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.
>
> I would not call this a broken PHY. It is a question of board
> design. If you have shorter tracks, you need a delay. If you have long
> tracks, you don't. Hence the four RGMII modes, so you can select if
> the delay is needed or not, depending on your board design.
>
> > Currently only some Pine64+ boards are known to have this issue.
>
> Design feature.
>
> Please remove all reference to bug.
>
> > This hack is said to disable RX relay for RTL8211E according to 
> > Realtek.
> > So implement it as RGMII-TXID mode.
>
> Do we know that the TX lines do have a delay after making this change?
> We need to be careful here. We will get into a mess if this is
> actually RGMII not RGMII_TXID, and somebody designs a board which
> needs RGMII-TXID.

In fact I'm not sure -- I'm even not sure that after making this change
there's no TX delay. The change is totally not documented, so I choose
to use a custom property in v1.

But Florian required me to use RGMII-TXID instead.

> > +#include <linux/of.h>
> >  #include <linux/phy.h>
> >  #include <linux/module.h>
>
> > +static int rtl8211e_config_init(struct phy_device *phydev)
> > +{
> > +	struct device *dev = &phydev->mdio.dev;
> > +	struct device_node *of_node = dev->of_node;
>
> You don't appear to use of_node, nor dev. Please remove, along with
> the header file.
>
>     Andrew
>
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