# Re: \[PATCH net v2\] net: phy: phy\_ethtool\_ksettings\_set: Don't discard phy\_start\_aneg's return

- From: Andrew Lunn \<andrew@lunn.ch\>
- Date: 2021-11-08 17:57:11 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/11/11215767
- Thread: https://ratatoskr.run/netdev/2021/11/11215670/t.md

```text
> It is BCM53125. Currently, you can set "mdix auto|off|on" which does
> not take any effect.  The chip will do what is its default depending
> on copper autonegotiation.
> 
> I am adding support for setting "mdix auto|off". I want the thing to error on "mdix on".
> Where would I add that check?

/* MDI or MDI-X status/control - if MDI/MDI_X/AUTO is set then
 * the driver is required to renegotiate link
 */
#define ETH_TP_MDI_INVALID	0x00 /* status: unknown; control: unsupported */
#define ETH_TP_MDI		0x01 /* status: MDI;     control: force MDI */
#define ETH_TP_MDI_X		0x02 /* status: MDI-X;   control: force MDI-X */
#define ETH_TP_MDI_AUTO		0x03 /*                  control: auto-select */

So there are three valid settings. And you are saying you only want to
implement two of them? If the hardware can do all three, you should
implement all three.

	  Andrew


```