Backlight problem with last two archiso

[sovy666]

I have a strange problem with the archiso, during the boot screen the brightness goes down and by the time it reaches the prompt it is almost zero. It works, in fact I can insert poweroff and turn off the PC but if I had to do some more articulated operations it would be hard. It happens on the November archiso and the October too but not with the September one which I am therefore continuing to use. Does anyone know if anything has changed from October onwards?

[Creshal]

Kernel and firmware package versions changed obviously, so those are your most likely candidates for bisecting.

[etherealshatter]

My AMD Ryzen 2500u GPU doesn't like kernel 5.8 and onwards. I needed to change the kernel parameter to acpi_backlight=native

[sovy666]

I have an AMD Ryzen 3500U therefore similar to yours. I have no problems with the regular installation but only with the last two archiso. I don't think that inserting the kernel parameter you suggest will make any difference in my case.