boot problem is now fixed on my Dell Latitude E7450: $ uname -a Linux [snip] 3.16.0-37-generic #51~14.04.1-Ubuntu SMP Wed May 6 15:23:14 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
boot problem is now fixed on my Dell Latitude E7450:
$ uname -a
Linux [snip] 3.16.0-37-generic #51~14.04.1-Ubuntu SMP Wed May 6 15:23:14 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux