> On Mon, Jan 14, 2019 at 1:18 AM Lorenzo Bianconi > <lorenzo.bianconi@xxxxxxxxxx> wrote: > > > > > On Sun, Jan 13, 2019 at 11:00 AM Lorenzo Bianconi > > > <lorenzo.bianconi@xxxxxxxxxx> wrote: > > > > > > > > > > > > > > > > > > > On Sun, Jan 13, 2019 at 5:33 AM, Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx> wrote: > > > > > > > > > > Direct. No VM used. This is the only peripheral causing this issue. > > > > > > > > > > Is the device connected to a usb3.0 port? If so, could you please try to connect the dongle to a 2.0 one? > > > > > > > > > > I tried through a USB 2.0 port. Shouldn't make a difference as they both use the xhci driver. > > > > > > > > > > > > > mt76x2u supports scatter-gather on usb 3.0 (not on 2.0) > > > Tried a USB 3 port. Same result. > > > > > > > > > Could you please double check if IOMMU is enabled? > > > > > > > > > > > > > Have you tried to disable it? Does it make any difference? > > > No idea how. UEFI doesn't seem to show anything similar. > > > > > > Similar bug report: https://bugzilla.kernel.org/show_bug.cgi?id=202241 > > > > You should be able to disable iommu using GRUB_CMDLINE_LINUX in > > /etc/default/grub (I guess setting iommu=off and reinstalling grub) > > https://wiki.gentoo.org/wiki/IOMMU_SWIOTLB > Yep. Working great now. I wonder what mt76 is doing to cause the crash though... Thanks for bisecting the issue. I think amd iommu does not support well usb scatter-gather (used by default in mt76u). I am working on a series in order to add the possibility to disable it. Regards, Lorenzo > > > > Regards, > > Lorenzo
