Hi Ahmad! On Wed, Jan 06, 2021 at 11:05:43AM +0100, Sascha Hauer wrote: >On Mon, Dec 21, 2020 at 01:32:50AM +0100, Ahmad Fatoum wrote: >> Linux doesn't seem to enforce a fixed order between phy_init and >> phy_power_on. The Linux dwc2 driver does power_on and then phy_init, >> which is the inverse of what barebox is currently doing. >> >> The PHYs normally used with dwc2 are written with this in mind. >> For example, our stm32-usbphyc driver fails to disable: >> >> ERROR: stm32-usbphyc 5a006000.usbphyc@5a006000.of: PLL not reset >> ERROR: phy1: phy exit failed --> -5 >> >> Because Linux does exit -> power_off, but barebox does power_off -> >> exit. >> >> Issue was raised upstream: >> https://lore.kernel.org/lkml/6cd01e79-fdc0-3bd4-32b5-a85142533f8a@pengutronix.de/T/#t >> >> Until this is settled, swap the order to follow what Linux does. >> This is suboptimal, because it means controller drivers have different >> order of the operations and that you can't combine arbitrary PHYs and >> controllers, but it seems unlikely we will support combinations that >> aren't supported by Linux in the first place anyway. > >This is valuable information and I don't want it to be lost, so instead >of applying this as a fixup I rewrote the subject to: > >usb: dwc2: swap order of phy_init and phy_power_on to what Linux does > >and applied it as a separate patch. With this patch applied, some stm32mp1 do seem to timeout when addressing the core. WARNING: dwc2 49000000.usb-otg@49000000.of: dwc2_core_reset: Timeout! Waiting for Core Soft Reset ERROR: dwc2 49000000.usb-otg@49000000.of: probe failed: Connection timed out When I revert this patch. Everything works fine again. Is it possible that we can revert it in mainline now? How can I reproduce the case this was fixing in the first place? Rergards, Michael -- 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 |