I have a Samsung RC510-AU laptop (NVIDIA OPTIMUS), most recently running fine with nouveau on F25. My root partition had insufficient space to do the upgrade to 26, so I reinstalled, but I'm having issues with the display card.

$ lspci | egrep 'NVIDIA|VGA'
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02)
02:00.0 3D controller: NVIDIA Corporation GT218M [GeForce 315M] (rev a2)

Fedora26 Live does not boot (completely freezes) unless I add "nouveau.modeset=0" to the kernel command line. This displays fine but is using software rendering (VESA). I see EDID modes in the log.

lsmod shows nouveau, but there is no nouveau entries in the kernel log.

$ uname -r

So I have software rendered VESA at the correct resolution, but I don't know why nouveau isn't working as of F26. Any assistance would be greatly appreciated.