Description of problem: After upgrading from 4.5.5 to 4.6.3, this laptop no longer boots. I can choose the kernel from grub, the screen goes black and a text cursor shows in the upper left corner, and then it just freezes (nothing happens). The proper graphical boot screen never shows. I tried removing "quiet" and adding "DEBUG", but that didn't show anything helpful either. Please note that this machine is affected by https://bugzilla.kernel.org/show_bug.cgi?id=110941 so that 4.5.5 only boots with intel_hwp=no_hwp. However, 4.6.3 no longer boots at all no matter if that option is specified or not. Version-Release number of selected component (if applicable): 4.6.3-300.fc24, x86_64 How reproducible: 100% Steps to Reproduce: 1. Install Fedora 24 fresh from Live CD (Workstation variant) _WITHOUT_ internet/network access 2. Reboot into installed system (you will need to edit the grub command line and add intel_pstate=no_hwp for the old kernel 4.5.5), enable networking and use: dnf update 3. Reboot into new kernel -> doesn't boot Actual results: Kernel doesn't boot. Adding intel_pstate=no_hwp doesn't help either. Expected results: Kernel boots Additional info:
The hardware in question is the Thinkpad Yoga 260 from Lenovo.
This is most likely caused by an Intel microcode update and is a duplicate of bug 1353103. If you add 'dis_ucode_ldr' to the kernel command line, does 4.6.3 boot?
I can confirm dis_ucode_ldr fixes it!
(In reply to Jonas Thiem from comment #3) > I can confirm dis_ucode_ldr fixes it! Good because it confirms the cause. But the cmdline parameter is unfortunately only a workaround. The fix will have to come from the BIOS/UEFI vendor, or with further updated microcode. *** This bug has been marked as a duplicate of bug 1353103 ***