Hello, I just noticed that USB controller drivers differ in the order in which they do phy_init and phy_power_on. For example: __dwc2_lowlevel_hw_enable(): ret = phy_power_on(hsotg->phy); if (ret == 0) ret = phy_init(hsotg->phy); dwc3_core_init(): ret = dwc3_core_soft_reset(dwc); // internally does phy_init(dwc->usb2_generic_phy); /* [snip] */ ret = phy_power_on(dwc->usb2_generic_phy); My initial assumption has been init -> power_on, but at least the phy-stm32-usbphyc (used with dwc2) is written with the assumption that exit -> power_off (and therefore power_on -> init). If they are swapped, disabling fails. So how was it meant to be? Cheers, Ahmad -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |