On 9/18/2022 12:13 PM, Lukas Wunner wrote:
[cc += Florian] On Mon, Aug 29, 2022 at 01:40:05PM +0200, Marek Szyprowski wrote:I've finally traced what has happened. I've double checked and indeed the 1758bde2e4aa commit fixed the issue on next-20220516 kernel and as such it has been merged to linus tree. Then the commit 744d23c71af3 ("net: phy: Warn about incorrect mdio_bus_phy_resume() state") has been merged to linus tree, which triggers a new warning during the suspend/resume cycle with smsc95xx driver. Please note, that the smsc95xx still works fine regardless that warning. However it look that the commit 1758bde2e4aa only hide a real problem, which the commit 744d23c71af3 warns about. Probably a proper fix for smsc95xx driver is to call phy_stop/start during suspend/resume cycle, like in similar patches for other drivers: https://lore.kernel.org/all/20220825023951.3220-1-f.fainelli@xxxxxxxxx/No, smsc95xx.c relies on mdio_bus_phy_{suspend,resume}() and there's no need to call phy_{stop,start}() > 744d23c71af3 was flawed and 6dbe852c379f has already fixed a portion of the fallout. However the WARN() condition still seems too broad and causes false positives such as in your case. In particular, mdio_bus_phy_suspend() may leave the device in PHY_UP state, so that's a legal state that needs to be exempted from the WARN().
How is that a legal state when the PHY should be suspended? Even if we are interrupt driven, the state machine should be stopped, does not mean that Wake-on-LAN or other activity interrupts should be disabled.
Does the issue still appear even after 6dbe852c379f? If it does, could you test whether exempting PHY_UP silences the gratuitous WARN splat? I.e.:
If you allow PHY_UP, then the warning becomes effectively useless, so I don't believe this is quite what you want to do here.
-- Florian
