Originally Posted by antikythera
.... please try that with IOMMU enabled and see if it makes any difference.
No joy !!! Still a black screen.
However, there are some additional factors.
Following is under F25:
1) The other project I was working on was adding 2 sata ports with a PCIe card using the "Marvell 88SE9128" chipset.
2) My GigaByte MB includes 2 "Marvell 88SE9172" soldered on chips to deliver esata to front and back panels.
3) Although things worked fine with the original 88SE9172 MB chips, adding the 88SE9128 via PCIe generated errors during boot. The boot was successful, but the new disks were not accessible.
4) Disabling IOMMU in the BIOS eliminates the boot errors and the disks are accessible. ( probably doesn't deal with root problem )
5) Since I really don't need to directly access devices from Virtual machines, I can accept this "solution"
Under F26 "rc8":
1) Was getting a black screen hang with F26 "rc8" boot prior to the new PCIe card installation
2) Discovered booting F26 "rc8" with IOMMU disabled is successful
3) I reenabled IOMMU and edited "modprobe.blacklist=sp5100_tco" into kernel command line
3) I now get the same(as F25) boot errors from the Marvell chip issues.
4) I get the same???(how can you tell) F26 black screen halt as before
4) Whether the halt the same or not, I do not get a successful F26 "rc8" boot
Thanks for the suggestion, but for now I can live without IOMMU. I'm willing to try other suggestions to actually isolate the issue. I would hate to see this continue into the final F26 release. Right now I'm just not sure how I would define the issue to BugZilla.