On 2 May 2018 at 11:18, Domenico Andreoli <domenico.andreoli@xxxxxxxxx> wrote: > On Wed, May 02, 2018 at 10:22:05AM +0200, Ard Biesheuvel wrote: >> On 2 May 2018 at 10:06, Domenico Andreoli <domenico.andreoli@xxxxxxxxx> wrote: >> > Dear all, >> > >> > my home machine stopped to boot starting from kernel version 4.12.7. >> > >> > The last message I read is about resetting some USB3 bus. It's 100% >> > reproducible also with any recent kernel up to 4.17.0-rc3. >> > >> > I bisected down to the following commit: >> > >> > commit 0e1f0eaed6c20db41ff61e024b361ee3ec9d686c (tag: my_broken_xhci) >> > Author: Marc Zyngier <marc.zyngier@xxxxxxx> >> > Date: Tue Aug 1 20:11:08 2017 -0500 >> > >> > xhci: Reset Renesas uPD72020x USB controller for 32-bit DMA issue >> > >> >> Hello Domenico, > > Sir.. > >> >> Long time no see :-) > > Instead I see you pretty much everywhere :P > >> >> Please refer to the following thread >> >> https://marc.info/?l=linux-usb&m=151872295419486 >> >> for some discussion on this topic, and a possible workaround. > > Interesting, thanks for the pointer! > > I'm happy to learn I've this nice piece of HW in my machine. It might > have at least some other issue while trying to hibernate (there is a > fair chance for it to abort the process because of some "business"). > > I tried the usb/uPD720202-reset branch from Marc (with some massaging > due to quirks now being >32) and my system boots again. I think it's > more because of the PCI reset is removed, I am not affected by the > original issue it was meant to fix. > Indeed. The majority of x86 machines never perform DMA above 4 GB in UEFI, so the issue does not occur, although it could still affect a kernel with IOMMU on kexec'ed from a kernel with IOMMU off. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
