[dapharsyde]

Hi Milhouse - 

Well, the bad news is that my testing box relies on the nvidia-legacy driver, so Xorg does not load in #1007x.  The good news, is that I tested this on another box I have which does not use nvidia-legacy, and the PS4 controller works as usual.

I guess I just need to wait for nvidia-legacy to be reenabled in these builds, and then I should be good to go.

That at least sounds promising.

Do you have any insight on why it was disabled, and if there are plans to bring back support?

Yes, DRIVER_PRIME is no longer supported by the 5.4 kernel, so the Nvidia drivers need to be updated - the xf86-video-nvidia driver changes were fairly trivial, but the xf86-video-nvidia-legacy driver looks like it will require more effort.

Unfortunately Nvidia drivers (both xf86-video-nvidia-legacy and xf86-video-nvidia) are always a PITA with new major kernels updates - this is a general problem with out-of-tree kernel drivers so not entirely unique to Nvidia (Realtek with their WiFi drivers are much the same) however Nvidia seem to fall afoul of kernel changes more often than anyone else.

I'm not sure when we'll get a working xf86-video-nvidia-legacy driver for 5.4 - it may only be once 5.4.0 is released, but that's not guaranteed as the last xf86-video-nvidia-legacy driver appeared in June 2018 so it's been 16 months and 10 major kernels without an update (4.15, 4.16, 4.17, 4.18, 4.19, 4.20, 5.0, 5.1, 5.2, 5.3 and now soon 5.4...).

It's possible a patch may turn up during the rc cycle - I'll keep looking and testing - but if not then we may have to proceed without xf86-video-nvidia-legacy support (until such time as Nvidia get their arse in gear). All official Nvidia support is due to end during Kodi 19 development (the Nouveau driver will be supported, as this support VAAPI) so eventually this official Nvidia driver nonsense will come to end (no doubt replaced by a different type of nonsense...) 

Ok thanks for the information.  I had a closer look, and this test box actually uses the regular xf86-video-nvidia driver, so hopefully that will be supported sooner, since as you mentioned, the driver changes were fairly trivial.  I guess now I wait for Nvidia...