Adding noapic to the kernel command line enabled shutdown/reboot/suspend/resume for me, but it wouldn't boot reliably.
This issue seems to be caused by a buggy driver for the Synopsys Designware I2C DMA controller, which is also used in the HP x360 and various other 2-in-1s and laptops. Blacklisting the dw_dmac kernel module enables shutdown, reboot, and suspend/resume for me on both Arch Linux and Ubuntu 14.10, but my fix should work on 14.04 and presumably other distros/versions as well.
Adding noapic to the kernel command line enabled shutdown/ reboot/ suspend/ resume for me, but it wouldn't boot reliably.
This issue seems to be caused by a buggy driver for the Synopsys Designware I2C DMA controller, which is also used in the HP x360 and various other 2-in-1s and laptops. Blacklisting the dw_dmac kernel module enables shutdown, reboot, and suspend/resume for me on both Arch Linux and Ubuntu 14.10, but my fix should work on 14.04 and presumably other distros/versions as well.