Lag/Stutter while changing screen brightness with keys

[UditDey]

I have a Dell Inspiron 3000 on which I installed elementary Juno a few days ago, alongside Windows 10. My experience has been smooth, but whenever I use the keyboard brightness keys to change the screen brightness, the brightness seems to stutter as it changes. It's always slow and laggy and sometimes it can take nearly 5 seconds after I press the key for the brightness to start changing, and if I keep either brightness key pressed the brightness pop up becomes unresponsive, the brightness doesn't change at all and the keyboard becomes unresponsive as well. This doesn't happen when I use the slider in System Setttings. I've used Windows 10, Manjaro with the i3 DE as well as Ubuntu on my laptop and never faced this problem before. I'm not sure if this is the right project to report this in, but it's seems relevant to the issue.

A quick Google search reveals that this seems to happen to many users with Dell laptops running Ubuntu, however in most cases the reason seems to be buggy ACPI and the solution is to disable the ACPI backlight driver with the acpi_backlight=vendor kernel parameter. However in my case ls /sys/class/backlight only lists intel_backlight and no ACPI driver, so my laptop's ACPI doesn't seem to be the issue. The kernel driver or the hardware is not the issue either because I tried "simulating" changing the backlight brightness from 0 to full with for i in seq 0 937; do echo $i > /sys/class/backlight/intel_backlight/brightness; sleep .001; done (937 is the value listed in intel_backlight/max_brightness) and this causes the brightness to increase smoothly with no stutter.

So it seems to be an issue with elementary, not the hardware. Looking into the power indicator's source reveals that elementary uses the gnome-settings-daemon so maybe gsd-media-keys or gsd-power is to blame?

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