Most of them during installation of Fedora on HP or other laptops would have encountered the problem that after the installation of the Operating system, Backlight of the laptop display would have been disabled, and it would be difficult to pass through initial steps to complete the installation, and i somehow managed to complete those steps by taking my laptop to a place full of brightness like house windows or terrace (during morning) and with the help of the reflection of that light completed those steps and then logged in successfully.
After you have done that, here is the solution to fix this issue when you will face next time you log in:
Step 1: Open your Terminal
Step 2: Type the following in your terminal
sudo gedit grub
Step 3: The grub file would have opened now with the Gedit text editor, now find the line which starts with “ GRUB_CMDLINE_LINUX =” and append the following text somewhere in the middle or at last or even at the first”
Step 4: Now save the file and close the text editor and get back to terminal and update the grub as follows
grub2-mkconfig -o /boot/grub2/grub.cfg
Step 5: After grub has been successfully updated, reboot the system and check whether are you getting the backlight working like charm and it should definitely work on HP laptops, even it should work on other laptops too. If not please comment below, we can seek for better solution.