+++ This bug was initially created as a clone of Bug #1409201 +++ Model: HP 15-ba028ur AMD® A10-9600p radeon r5, 10 compute cores 4c+6g × 4 ERROR MESSAGES: AMD-Vi: Completion-Wait loop timed out and AMD-Vi: Event logged [IOTLB_INV_TIMEOUT device=... With kernels 4.7.* the system boots fine. When I boot the Fedora 25 LXDE Live CD (64-bit EFI version), I get the same errors (and errors SQUASHFS error: Unable to read data cache entry..., SQUASHFS error: Unable to read page, block...) . But when I add "iommu=soft" to kernel parameters, the Live CD boots fine!
More info: https://lists.freedesktop.org/archives/amd-gfx/2017-March/006490.html
Similar bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1448121
PATCH that fixes this problem: https://patchwork.freedesktop.org/patch/157327/
Created attachment 1293333 [details] Patch
We apologize for the inconvenience. There is a large number of bugs to go through and several of them have gone stale. The kernel moves very fast so bugs may get fixed as part of a kernel update. Due to this, we are doing a mass bug update across all of the Fedora 26 kernel bugs. Fedora 26 has now been rebased to 4.15.4-200.fc26. Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel. If you have moved on to Fedora 27, and are still experiencing this issue, please change the version to Fedora 27. If you experience different issues, please open a new bug report for those.
It has been fixed.