Hello Michael, On 21.03.22 23:17, Michael Grzeschik wrote: > 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@xxxxxxxxxxx: 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@xxxxxxxxxxxxxx/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@xxxxxxxxxxx: dwc2_core_reset: Timeout! Waiting for Core Soft Reset > ERROR: dwc2 49000000.usb-otg@xxxxxxxxxxx: 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? Since 0e37f94fbe1b ("phy: stm32: sync with upstream"), the phy-stm32-usbphyc now has no poweron/poweroff callbacks, so a revert seems to only slightly change timing. I'd suggest you dig some more. > How can I reproduce the case this was fixing in the first place? The case was that barebox calls poweron/init in a different order than Linux. This point is moot now though because poweron is no longer provided by the driver. Cheers, Ahmad > > Rergards, > Michael > > > _______________________________________________ > barebox mailing list > barebox@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/barebox -- 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 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
