Re: [PATCH] net: phy: Trigger link_change_notify on PHY_HALTED
From: Heiner Kallweit <hkallweit1@gmail.com>
Date: 2021-01-05 16:59:10
On 05.01.2021 17:11, Marek Vasut wrote:
In case the PHY transitions to PHY_HALTED state in phy_stop(), the link_change_notify callback is not triggered. That's because the phydev->state = PHY_HALTED in phy_stop() is assigned first, and phy_state_machine() is called afterward. For phy_state_machine(), no state transition happens, because old_state = PHY_HALTED and phy_dev->state = PHY_HALTED.
There are a few formal issues with this patch: - It misses a net/net-next annotation. If it's meant to be a fix, then the Fixes tag is missing. I just checked the existing link_change_notify handlers and nobody is interested in state transitions to PHY_HALTED. Therefore I think it's more of an improvement. However AFAICS net-next is still closed. - The maintainers should be in To: and the list(s) on cc. - Seems that Russell and Jakub are missing as maintainers.
quoted hunk ↗ jump to hunk
Signed-off-by: Marek Vasut <marex@denx.de> Cc: Andrew Lunn <andrew@lunn.ch> Cc: David S. Miller <davem@davemloft.net> Cc: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/net/phy/phy.c | 10 ++++++++++ 1 file changed, 10 insertions(+)diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 45f75533c47c..fca8c3eebc5d 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c@@ -1004,6 +1004,7 @@ EXPORT_SYMBOL(phy_free_interrupt); void phy_stop(struct phy_device *phydev) { struct net_device *dev = phydev->attached_dev; + enum phy_state old_state; if (!phy_is_started(phydev) && phydev->state != PHY_DOWN) { WARN(1, "called from state %s\n",@@ -1021,8 +1022,17 @@ void phy_stop(struct phy_device *phydev) if (phydev->sfp_bus) sfp_upstream_stop(phydev->sfp_bus); + old_state = phydev->state; phydev->state = PHY_HALTED; + if (old_state != phydev->state) {
This check shouldn't be needed because it shouldn't happen that phy_stop() is called from status PHY_HALTED. In this case the WARN() a few lines above would have fired already.
+ phydev_err(phydev, "PHY state change %s -> %s\n", + phy_state_to_str(old_state), + phy_state_to_str(phydev->state)); + if (phydev->drv && phydev->drv->link_change_notify) + phydev->drv->link_change_notify(phydev);
Instead of duplicating this code it could be factored out into a small helper that is used by phy_stop() and phy_state_machine().
+ } + mutex_unlock(&phydev->lock); phy_state_machine(&phydev->state_queue.work);