[PATCH v2] net: phy: Support overriding Auto Negotiation timeout with env variable
Siddharth Vadapalli
s-vadapalli at ti.com
Wed Jul 23 08:26:42 CEST 2025
The Auto Negotiation procedure between two Ethernet PHYs consists of
determining the best commonly supported parameters among Speed,
Duplex Mode and Flow Control.
The time taken for this procedure is not only dependent on the local
PHY used, but also on the link-partner PHY.
While a timeout can be specified in the form of a "CONFIG" on the basis
of the local PHY present on the device, since the timeout also depends
on the link-partner PHY, it might be necessary to modify the timeout.
To avoid rebuilding the bootloader for a given device, just because it
may be connected to various link-partner PHYs, each with a different
timeout, introduce an environment variable named "phy_aneg_timeout" and
override "CONFIG_PHY_ANEG_TIMEOUT" with "phy_aneg_timeout".
Signed-off-by: Siddharth Vadapalli <s-vadapalli at ti.com>
---
Hello,
This patch is based on commit
7598b469c16 Merge tag 'u-boot-dfu-next-20250703' of https://source.denx.de/u-boot/custodians/u-boot-dfu into next
of the next branch of Mainline U-Boot.
v1 of this patch is at:
https://patchwork.ozlabs.org/project/uboot/patch/20250722060554.352952-1-s-vadapalli@ti.com/
Changes since v1:
- Switched to env_get_ulong() based on feedback from Marek Vasut at:
https://patchwork.ozlabs.org/project/uboot/patch/20250722060554.352952-1-s-vadapalli@ti.com/#3550426
- Addressed feedback from Quentin Schulz at:
https://patchwork.ozlabs.org/project/uboot/patch/20250722060554.352952-1-s-vadapalli@ti.com/#3550263
by performing the following changes:
1) Updated drivers/net/phy/Kconfig by documenting that phy_aneg_timeout
env variable can override the value of CONFIG_PHY_ANEG_TIMEOUT
2) Updated doc/usage/environment.rst by documenting the base and unit
of phy_aneg_timeout
3) Updated drivers/net/phy/aquantia.c and drivers/net/xilinx_axi_emac.c
to support overriding CONFIG_PHY_ANEG_TIMEOUT with phy_aneg_timeout
Patch has been tested on J784S4-EVM validating the following cases:
1. PHY Auto-Negotiation performed with "phy_aneg_timeout" unset.
CONFIG_PHY_TIMEOUT with a value of 4,000 takes effect.
=> Auto Negotiation succeeds
2. PHY Auto-Negotiation performed with "phy_aneg_timeout" set to 20,000.
"phy_aneg_timeout" overrides CONFIG_PHY_TIMEOUT.
[Higher value than default specified by CONFIG_PHY_ANEG_TIMEOUT]
=> Auto Negotiation succeeds
3. PHY Auto-Negotiation performed with "phy_aneg_timeout" set to 200.
"phy_aneg_timeout" overrides CONFIG_PHY_TIMEOUT.
[Lower value than default specified by CONFIG_PHY_ANEG_TIMEOUT]
=> Auto Negotiation times out
Test Logs:
https://gist.github.com/Siddharth-Vadapalli-at-TI/3e9cbdfedc541032768b14c15244f590
Regards,
Siddharth.
doc/usage/environment.rst | 9 +++++++++
drivers/net/phy/Kconfig | 4 +++-
drivers/net/phy/aquantia.c | 8 +++++---
drivers/net/phy/phy.c | 7 +++++--
drivers/net/xilinx_axi_emac.c | 7 +++++--
5 files changed, 27 insertions(+), 8 deletions(-)
diff --git a/doc/usage/environment.rst b/doc/usage/environment.rst
index bb6c351b441..b48c11faffa 100644
--- a/doc/usage/environment.rst
+++ b/doc/usage/environment.rst
@@ -335,6 +335,15 @@ netretry
Useful on scripts which control the retry operation
themselves.
+phy_aneg_timeout
+ If set, the specified value will override CONFIG_PHY_ANEG_TIMEOUT
+ which defaults to 4000 (decimal) millisecond. This variable has
+ the same base and unit as CONFIG_PHY_ANEG_TIMEOUT.
+ The default value of CONFIG_PHY_ANEG_TIMEOUT may be sufficient for
+ most use-cases, but certain link-partners may require a larger
+ timeout due to the Ethernet PHY they use. Alternatively, the timeout
+ can be reduced as well if the use-case demands it.
+
rng_seed_size
Size of random value added to device-tree node /chosen/rng-seed.
This variable is given as a decimal number.
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 3132718e4f8..7fa1a89fca4 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -23,7 +23,9 @@ config PHY_ANEG_TIMEOUT
int "PHY auto-negotiation timeout"
default 4000
help
- Default PHY auto-negotiation timeout.
+ Default PHY auto-negotiation timeout in millisecond (decimal).
+ This can be overridden by the phy_aneg_timeout environment
+ variable that has the same base and unit.
if PHY_ADDR_ENABLE
config PHY_ADDR
diff --git a/drivers/net/phy/aquantia.c b/drivers/net/phy/aquantia.c
index d2db8d9f792..72f29824468 100644
--- a/drivers/net/phy/aquantia.c
+++ b/drivers/net/phy/aquantia.c
@@ -552,13 +552,15 @@ int aquantia_config(struct phy_device *phydev)
int aquantia_startup(struct phy_device *phydev)
{
u32 speed;
- int i = 0;
+ ulong i = 0;
int reg;
phydev->duplex = DUPLEX_FULL;
/* if the AN is still in progress, wait till timeout. */
if (!aquantia_link_is_up(phydev)) {
+ ulong aneg_timeout = env_get_ulong("phy_aneg_timeout", 10,
+ CONFIG_PHY_ANEG_TIMEOUT);
printf("%s Waiting for PHY auto negotiation to complete",
phydev->dev->name);
do {
@@ -566,9 +568,9 @@ int aquantia_startup(struct phy_device *phydev)
if ((i++ % 500) == 0)
printf(".");
} while (!aquantia_link_is_up(phydev) &&
- i < (4 * CONFIG_PHY_ANEG_TIMEOUT));
+ i < (4 * aneg_timeout));
- if (i > CONFIG_PHY_ANEG_TIMEOUT)
+ if (i > aneg_timeout)
printf(" TIMEOUT !\n");
}
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index e6fed8c41d7..b1c93bedd28 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -9,6 +9,7 @@
*/
#include <console.h>
#include <dm.h>
+#include <env.h>
#include <log.h>
#include <malloc.h>
#include <net.h>
@@ -242,7 +243,9 @@ int genphy_update_link(struct phy_device *phydev)
if ((phydev->autoneg == AUTONEG_ENABLE) &&
!(mii_reg & BMSR_ANEGCOMPLETE)) {
- int i = 0;
+ ulong i = 0;
+ ulong aneg_timeout = env_get_ulong("phy_aneg_timeout", 10,
+ CONFIG_PHY_ANEG_TIMEOUT);
printf("%s Waiting for PHY auto negotiation to complete",
phydev->dev->name);
@@ -250,7 +253,7 @@ int genphy_update_link(struct phy_device *phydev)
/*
* Timeout reached ?
*/
- if (i > (CONFIG_PHY_ANEG_TIMEOUT / 50)) {
+ if (i > (aneg_timeout / 50)) {
printf(" TIMEOUT !\n");
phydev->link = 0;
return -ETIMEDOUT;
diff --git a/drivers/net/xilinx_axi_emac.c b/drivers/net/xilinx_axi_emac.c
index 4d87e2d1f36..e95b407e43c 100644
--- a/drivers/net/xilinx_axi_emac.c
+++ b/drivers/net/xilinx_axi_emac.c
@@ -343,7 +343,10 @@ static int axiemac_phy_init(struct udevice *dev)
static int pcs_pma_startup(struct axidma_priv *priv)
{
- u32 rc, retry_cnt = 0;
+ ulong aneg_timeout = env_get_ulong("phy_aneg_timeout", 10,
+ CONFIG_PHY_ANEG_TIMEOUT);
+ ulong retry_cnt = 0;
+ u32 rc;
u16 mii_reg;
rc = phyread(priv, priv->pcsaddr, MII_BMCR, &mii_reg);
@@ -361,7 +364,7 @@ static int pcs_pma_startup(struct axidma_priv *priv)
* and the external PHY is not obtained.
*/
debug("axiemac: waiting for link status of the PCS/PMA PHY");
- while (retry_cnt * 10 < CONFIG_PHY_ANEG_TIMEOUT) {
+ while (retry_cnt * 10 < aneg_timeout) {
rc = phyread(priv, priv->pcsaddr, MII_BMSR, &mii_reg);
if ((mii_reg & BMSR_LSTATUS) && mii_reg != 0xffff && !rc) {
debug(".Done\n");
--
2.34.1
More information about the U-Boot
mailing list