On Thu, Sep 11, 2025 at 07:55:13AM -0700, Jakub Kicinski wrote: > On Thu, 11 Sep 2025 15:39:20 +0100 Russell King (Oracle) wrote: > > I'm not surprised. I'm guessing phylib is using polled mode, and > > removing the suspend/resume handling likely means that it's at the > > mercy of the timings of the phylib state machine running (which is > > what is complaining here) vs the MDIO bus being available for use. > > > > Given that this happens, I'm convinced that the original patch is > > the wrong approach. The driver needs the phylink suspend/resume > > calls to shutdown and restart phylib polling, and the resume call > > needs to be placed in such a location that the MDIO bus is already > > accessible. > > We keep having issues with rtnl_lock taken from resume. > Honestly, I'm not sure anyone has found a good solution, yet. > Mostly people just don't implement runtime PM. > > If we were able to pass optional context to suspend/resume > we could implement conditional locking. We'd lose a lot of > self-respect but it'd make fixing such bugs easier.. Normal drivers have the option of separate callbacks for runtime PM vs system suspend/resume states. It seems USB doesn't, just munging everything into one pair of suspend and resume ops without any way of telling them apart. I suggest that is part of the problem here. However, I'm not a USB expert, so... -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
