This problem appears again in XPS 13 9343 (sputnik 2015 edition), on stock Ubuntu 15.04:
Linux laminato 3.19.0-16-generic #16-Ubuntu SMP Thu Apr 30 16:09:58 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
I'm using EFI boot
This problem appears again in XPS 13 9343 (sputnik 2015 edition), on stock Ubuntu 15.04:
Linux laminato 3.19.0-16-generic #16-Ubuntu SMP Thu Apr 30 16:09:58 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
I'm using EFI boot