Bug is present for me in Xubuntu 18.04 (Kernel: 4.15.0-20-generic x86; Xfce 4.12.3; Graphics Card: Advanced Micro Devices [AMD/ATI] Mullins [Radeon R4/R5 Graphics]).
Black screen (so no backlight at all) after resume, but only in case the suspend was initiated by lid closing. Replacing lightdm or light-locker didnt solve the problem.
Solution offered in #14 by Piotr Admin (piotr-wroclaw) solves it, but also removes the opportunity to set lid action from xfce power manager and moreover screen is not locked while laptop sleeps.
Bug is present for me in Xubuntu 18.04 (Kernel: 4.15.0-20-generic x86; Xfce 4.12.3; Graphics Card: Advanced Micro Devices [AMD/ATI] Mullins [Radeon R4/R5 Graphics]).
Black screen (so no backlight at all) after resume, but only in case the suspend was initiated by lid closing. Replacing lightdm or light-locker didnt solve the problem.
Solution offered in #14 by Piotr Admin (piotr-wroclaw) solves it, but also removes the opportunity to set lid action from xfce power manager and moreover screen is not locked while laptop sleeps.