Description of problem:
Screen brightness stopped working with kernel 4.7.2 on MSI GE60 laptop. It works fine with 4.6.7 and older kernels (as long as I can remember it has been working). When adding "acpi_osi=" to the GRUB command line it works also in kernel 4.7.2.

Version-Release number of selected component (if applicable):
4.7.2-201.fc24.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Boot PC with 4.7.2 kernel
2. Hit Fn+Up, Fn+Down

Actual results:
Brightness doesn't change

Expected results:
Brightness should change

Additional info:

This is an MSI GE60 laptop. 
Brightness change works with 4.6 and older kernels.

"acpi_osi=" (null) kernel command line fixes it in 4.7.2 kernel for this laptop.
Command lines "acpi_osi=Linux" "video.use_native_backlight=1" and "acpi_backlight=vendor" do not work.
Previous kernels 4.6 and older didn't need any command line options.

Output with working backlight:

[root@msi ~]# ls /sys/class/backlight
acpi_video0  acpi_video1  intel_backlight

Output with non-working backligt:

[root@msi ~]# ls /sys/class/backlight
intel_backlight



[root@msi ~]# grep '.*' /sys/class/dmi/id/*_* 2> /dev/null
/sys/class/dmi/id/bios_date:03/12/2013
/sys/class/dmi/id/bios_vendor:American Megatrends Inc.
/sys/class/dmi/id/bios_version:E16GAIMS.514
/sys/class/dmi/id/board_asset_tag:To be filled by O.E.M.
/sys/class/dmi/id/board_name:MS-16GA
/sys/class/dmi/id/board_serial:BSS-0123456789
/sys/class/dmi/id/board_vendor:Micro-Star International Co., Ltd.
/sys/class/dmi/id/board_version:REV:1.0
/sys/class/dmi/id/chassis_asset_tag:No Asset Tag
/sys/class/dmi/id/chassis_serial:None
/sys/class/dmi/id/chassis_type:10
/sys/class/dmi/id/chassis_vendor:Micro-Star International Co., Ltd.
/sys/class/dmi/id/chassis_version:N/A
/sys/class/dmi/id/product_name:GE60 0NC\0ND
/sys/class/dmi/id/product_serial:FFFFFFFF
/sys/class/dmi/id/product_uuid:03000200-0400-0500-0006-000700080009
/sys/class/dmi/id/product_version:REV:1.0
/sys/class/dmi/id/sys_vendor:Micro-Star International Co., Ltd.


[root@msi etc]# lsmod|grep msi
msi_wmi                16384  0
wmi                    16384  2 msi_wmi,mxm_wmi
msi_laptop             16384  0
rfkill                 24576  8 cfg80211,msi_laptop,bluetooth
sparse_keymap          16384  2 msi_laptop,msi_wmi
video                  40960  3 i915,msi_laptop,msi_wmi

The msi_wmi module seems a bit broken for this laptop. It has always printed "msi_wmi: Unknown event received" when changing brightness (and still does), but it doesn't seem to matter for the brightness.