This is a note to let you know that I've just added the patch titled
net: usb: asix: suspend embedded PHY if external is used
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-usb-asix-suspend-embedded-phy-if-external-is-use.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 88cda0d3d909d42056d85253ea0dda10a18459f8
Author: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Date: Fri Mar 11 09:50:14 2022 +0100
net: usb: asix: suspend embedded PHY if external is used
[ Upstream commit 4d17d43de9d186150b3289ce99d7a79fcff202f9 ]
In case external PHY is used, we need to take care of embedded PHY.
Since there are no methods to disable this PHY from the MAC side and
keeping RMII reference clock, we need to suspend it.
This patch will reduce electrical noise (PHY is continuing to send FLPs)
and power consumption by 0,22W.
Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: cbc17e7802f5 ("net: fec: Set mac_managed_pm during probe")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/usb/asix.h b/drivers/net/usb/asix.h
index c126df1c13ee7..9da88e132d516 100644
--- a/drivers/net/usb/asix.h
+++ b/drivers/net/usb/asix.h
@@ -157,6 +157,8 @@
#define AX_EEPROM_MAGIC 0xdeadbeef
#define AX_EEPROM_LEN 0x200
+#define AX_EMBD_PHY_ADDR 0x10
+
/* This structure cannot exceed sizeof(unsigned long [5]) AKA 20 bytes */
struct asix_data {
u8 multi_filter[AX_MCAST_FILTER_SIZE];
@@ -181,6 +183,7 @@ 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;
char phy_name[20];
bool embd_phy;
diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index 396505396a2e4..254637c2b1830 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -698,6 +698,22 @@ static int ax88772_init_phy(struct usbnet *dev)
phy_attached_info(priv->phydev);
+ if (priv->embd_phy)
+ return 0;
+
+ /* In case main PHY is not the embedded PHY and MAC is RMII clock
+ * provider, we need to suspend embedded PHY by keeping PLL enabled
+ * (AX_SWRESET_IPPD == 0).
+ */
+ priv->phydev_int = mdiobus_get_phy(priv->mdio, AX_EMBD_PHY_ADDR);
+ if (!priv->phydev_int) {
+ netdev_err(dev->net, "Could not find internal PHY\n");
+ return -ENODEV;
+ }
+
+ priv->phydev_int->mac_managed_pm = 1;
+ phy_suspend(priv->phydev_int);
+
return 0;
}
@@ -753,7 +769,7 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
return ret;
priv->phy_addr = ret;
- priv->embd_phy = ((priv->phy_addr & 0x1f) == 0x10);
+ priv->embd_phy = ((priv->phy_addr & 0x1f) == AX_EMBD_PHY_ADDR);
ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &chipcode, 0);
if (ret < 0) {
