Re: [PATCH net-next v1 4/4] net: usb: asix: suspend internal PHY if external is used

From: Andrew Lunn
Date: Thu Mar 10 2022 - 14:19:52 EST


On Thu, Mar 10, 2022 at 12:44:34PM +0100, Oleksij Rempel wrote:
> In case external PHY is used, we need to take care of internal PHY.
> Since there are no methods to disable this PHY from the MAC side, we
> need to suspend it.
> This we reduce electrical noise (PHY is continuing to send FLPs) and power
> consumption by 0,22W.
>
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> ---
> drivers/net/usb/asix.h | 3 +++
> drivers/net/usb/asix_devices.c | 16 +++++++++++++++-
> 2 files changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/usb/asix.h b/drivers/net/usb/asix.h
> index 072760d76a72..8a087205355d 100644
> --- a/drivers/net/usb/asix.h
> +++ b/drivers/net/usb/asix.h
> @@ -158,6 +158,8 @@
> #define AX_EEPROM_MAGIC 0xdeadbeef
> #define AX_EEPROM_LEN 0x200
>
> +#define AX_INTERNAL_PHY_ADDR 0x10
> +
> /* This structure cannot exceed sizeof(unsigned long [5]) AKA 20 bytes */
> struct asix_data {
> u8 multi_filter[AX_MCAST_FILTER_SIZE];
> @@ -183,6 +185,7 @@ struct asix_common_private {
> struct asix_rx_fixup_info rx_fixup_info;
> struct mii_bus *mdio;
> struct phy_device *phydev;
> + struct phy_device *phydev_int;
> u16 phy_addr;
> bool embd_phy;
> u8 chipcode;
> diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
> index fb617eb551bb..2c63fbe32ca2 100644
> --- a/drivers/net/usb/asix_devices.c
> +++ b/drivers/net/usb/asix_devices.c
> @@ -679,6 +679,20 @@ static int ax88772_init_phy(struct usbnet *dev)
>
> phy_attached_info(priv->phydev);
>
> + if (priv->embd_phy)
> + return 0;

Minor nit pick: There appears to be some inconsistency with internal
and embedded. I think they are meant to mean the same thing? Maybe
replace internal with embedded in this patch?

The rest looks O.K.

Andrew