I have an Dell Inspiron 5770 laptop with Intel UHD Graphics 620 and discrete AMD ATI Radeon R7.
With the 5.3 series I would get i915 fifo overrun messages that manifested as a screen flash - these happened infrequently. With the latest 5.4 I've now been getting lockups.
[ 7294.702710] i915 0000:00:02.0: GPU recovery timed out, cancelling all in-flight rendering.
[ 7294.702895] i915 0000:00:02.0: Resetting chip for hang on rcs0
[ 7295.198781] pcieport 0000:00:1c.0: Intel SPT PCH root port ACS workaround enabled
[ 7295.206230] [drm] PCIE GART of 256M enabled (table at 0x000000F400000000).
[ 7295.211065] amdgpu: [powerplay] can't get the mac of 5
[ 7295.414739] rfkill: input handler enabled
[ 7296.686784] i915 0000:00:02.0: GPU recovery timed out, cancelling all in-flight rendering.
[ 7296.687530] i915 0000:00:02.0: Resetting chip for hang on rcs0
I've had to reboot the laptop to recover each time this has happened. As a temporary workaround I've enabled my discrete AMD card and will see if that works or not.
Side rant: the Linux kernel has become increasingly unstable with the 5.0+ series. I've actually had data loss thanks to the poor quality of kernel development. This isn't the responsibility of the Solus team of course - I really like Solus and Budgie and the curated rolling release model. But with crappy quality control in upstream Linux kernel development you might start thinking seriously about offering only an LTS kernel. I'm probably going to have to switch to the -lts package anyways if my AMD workaround fails.