Subject: Re: [PATCH net v2 0/2] Fix 'ethtool --show-eee' during initial stage

From: Heiner Kallweit <[email-masked]>
Date: Fri, 15 Nov 2024 21:35:25 +0100

On 15.11.2024 15:12, Russell King (Oracle) wrote:
> On Fri, Nov 15, 2024 at 02:41:54PM +0100, Heiner Kallweit wrote:
>> On 15.11.2024 12:11, Choong Yong Liang wrote:
>>> From: Choong Yong Liang <[email-masked]>
>>>
>>> When the MAC boots up with a Marvell PHY and phy_support_eee() is implemented,
>>> the 'ethtool --show-eee' command shows that EEE is enabled, but in actuality,
>>> the driver side is disabled. If we try to enable EEE through
>>> 'ethtool --set-eee' for a Marvell PHY, nothing happens because the eee_cfg
>>> matches the setting required to enable EEE in ethnl_set_eee().
>>>
>>> This patch series will remove phydev->eee_enabled and replace it with
>>> eee_cfg.eee_enabled. When performing genphy_c45_an_config_eee_aneg(), it
>>> will follow the master configuration to have software and hardware in sync,
>>> allowing 'ethtool --show-eee' to display the correct value during the
>>> initial stage.
>>>
>>> v2 changes:
>>>  - Implement the prototype suggested by Russell
>>>  - Check EEE before calling phy_support_eee()
>>>
>>> Thanks to Russell for the proposed prototype in [1].
>>>
>>> Reference:
>>> [1] https://patchwork.kernel.org/comment/26121323/
>>>
>>> Choong Yong Liang (2):
>>>   net: phy: replace phydev->eee_enabled with eee_cfg.eee_enabled
>>>   net: stmmac: set initial EEE policy configuration
>>>
>>>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |  3 +++
>>>  drivers/net/phy/phy-c45.c                         | 11 +++++------
>>>  drivers/net/phy/phy_device.c                      |  6 +++---
>>>  include/linux/phy.h                               |  5 ++---
>>>  4 files changed, 13 insertions(+), 12 deletions(-)
>>>
>>
>> Russell submitted the proposed patch already:
>> https://patchwork.kernel.org/project/netdevbpf/patch/[email-masked]/
>> So there's no need for your patch 1.
> 
> Patch 1 is an updated version of that patch, minus my authorship and of
> course no sign-off. I've already marked this series as requiring changes
> in patchwork (hopefully, if I did it correctly.)
> 

The updated version adds an argument to genphy_c45_an_config_eee_aneg(),
and I wonder whether we can do better, as this results in several calls
with the same argument. The following is an alternative, to be applied
on top of your original patch. I don't have a clear preference, though.

---
 drivers/net/phy/phy.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 8876f3673..22c9bbebb 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1682,11 +1682,10 @@ EXPORT_SYMBOL(phy_ethtool_get_eee);
  * configuration.
  */
 static void phy_ethtool_set_eee_noneg(struct phy_device *phydev,
-				      struct ethtool_keee *data)
+				      struct ethtool_keee *old_cfg)
 {
-	if (phydev->eee_cfg.tx_lpi_enabled != data->tx_lpi_enabled ||
-	    phydev->eee_cfg.tx_lpi_timer != data->tx_lpi_timer) {
-		eee_to_eeecfg(&phydev->eee_cfg, data);
+	if (phydev->eee_cfg.tx_lpi_enabled != old_cfg->tx_lpi_enabled ||
+	    phydev->eee_cfg.tx_lpi_timer != old_cfg->tx_lpi_timer) {
 		phydev->enable_tx_lpi = eeecfg_mac_can_tx_lpi(&phydev->eee_cfg);
 		if (phydev->link) {
 			phydev->link = false;
@@ -1706,21 +1705,27 @@ static void phy_ethtool_set_eee_noneg(struct phy_device *phydev,
  */
 int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_keee *data)
 {
+	struct eee_config old_cfg;
 	int ret;
 
 	if (!phydev->drv)
 		return -EIO;
 
+	old_cfg = phydev->eee_cfg;
+	eee_to_eeecfg(&phydev->eee_cfg, data);
+
 	mutex_lock(&phydev->lock);
 	ret = genphy_c45_ethtool_set_eee(phydev, data);
-	if (ret >= 0) {
-		if (ret == 0)
-			phy_ethtool_set_eee_noneg(phydev, data);
-		eee_to_eeecfg(&phydev->eee_cfg, data);
-	}
+	if (ret == 0)
+		phy_ethtool_set_eee_noneg(phydev, data);
 	mutex_unlock(&phydev->lock);
 
-	return ret < 0 ? ret : 0;
+	if (ret < 0) {
+		phydev->eee_cfg = old_cfg;
+		return ret;
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL(phy_ethtool_set_eee);
 
-- 
2.47.0