HP envy laptop cannot adjust screen brightness

[jimbo45]

Hi there
Screen brightness doesn';t work with centos 7 / kernel 3. Laptop HP envy with INTEL graphics. Screen stays about 50% bright --OK not impossible to read but it would be nice to have this working.

Also KDE power profiles don't work.

Kernel 4 brightness works fine but other issues have made me go back to the older kernel.

Any ideas.

Cheers
jimbo