Upgrading to Kernel 15.16 left me with a near unusable machine. I wanted to give an update because this was such a frustrating fix for the blinking screen present on my Dell Laptop. Actually the fix was easy, but researching the issue was time consuming. It appears the new Linux Kernnel 15.16 comes with some free issues for Dell laptop users. My Dell laptop began exhibiting a strange flickering and logout bug immediately after upgrade to the latest Kernel. To fix the issue, I simply rolled back the Kernel to 15.15 that originally came with Ubuntu, but not without first trying a couple suggestions provided in other posts.
Here is what I did that did not work:
This was very difficult to execute as well because not only did the laptop do the screen flicker, but it also logged me out asking for credentials again. So just as I was about to get the GRUB_CMDLINE_LINUX_DEFAULT value updated, I would get booted and have to get back into complete typing the line, or saving, etc.
In addition to this suggestion above, I read from another post that changing intel_idle.max_cstate=2 to =4 would fix the issue. Again, it did not.
The real fix, was roll back to a usable kernel by hitting the “Esc” key during boot, getting to the Grub bootloader, selecting Advanced options for Ubuntu.
This is an old image, but as you can see below, you can just arrow up or down to select which version of the Kernel you want to boot.
I suppose I need to reach out to the development team with my concerns that the Kernel breaks video display in 2015 dells with i915 graphics cards.