Sometimes when my machine come back from suspend the hw acceleration is stopped to work. Kernel messages: https://bugzilla.mozilla.org/attachment.cgi?id=8989152

I updated my system to Ubuntu 18.04 based Linux Mint 19 recently so I have this X:
X.Org X Server 1.19.6

I used radeon driver that time, but now I switched to AMDGPU driver and 4.17 kernel. This laptop has two video cards, one integrated from Intel and another from AMD.

Release Date: 2017-12-20
[    62.938] X Protocol Version 11, Revision 0
[    62.938] Build Operating System: Linux 4.4.0-119-generic x86_64 Ubuntu
[    62.938] Current Operating System: Linux godzilla 4.17.0-041700-generic #201806032231 SMP Sun Jun 3 22:33:34 UTC 2018 x86_64
[    62.938] Kernel command line: BOOT_IMAGE=/vmlinuz-4.17.0-041700-generic root=/dev/mapper/main-root ro rootflags=subvol=@ elevator=deadline zswap.enabled=1 pti=1 ibrs=1 ibpb=1 radeon.si_support=0 radeon.cik_support=0 amdgpu.si_support=1 amdgpu.cik_support=1 amdgpu.dc=1 quiet splash vt.handoff=1
[    62.938] Build Date: 13 April 2018  08:07:36PM
[    62.938] xorg-server 2:1.19.6-1ubuntu4 (For technical support please see http://www.ubuntu.com/support) 

Mesa:
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Haswell Mobile 
OpenGL core profile version string: 4.5 (Core Profile) Mesa 18.0.0-rc5
OpenGL core profile shading language version string: 4.50

As you can see from the kernel parameters I was manage to use amdgpu driver with the build in AMD GPU. Time by time something happen (maybe related to ACPI events) and Firefox is stop working. I have to restart Firefox, but I got this error in terminal:

DRI_PRIME=1 firefox
firefox: ../../../src/amd/addrlib/r800/siaddrlib.cpp:2294: int Addr::V1::SiLib::DecodeGbRegs(const ADDR_REGISTER_VALUE*): Assertion `!"Unhandled case"' failed.
ExceptionHandler::GenerateDump cloned child 7263
ExceptionHandler::SendContinueSignalToChild sent continue signal to child
ExceptionHandler::WaitForContinueSignal waiting for continue signal...

Also glxinfo has problem:
DRI_PRIME=1 glxinfo 
name of display: :0
glxinfo: ../../../src/amd/addrlib/r800/siaddrlib.cpp:2294: int Addr::V1::SiLib::DecodeGbRegs(const ADDR_REGISTER_VALUE*): Assertion `!"Unhandled case"' failed.
Félbeszakítva (core készült)
kami@godzilla ~ $ 

-----------------------------

name of display: :0
display: :0  screen: 0
direct rendering: Yes
server glx vendor string: SGI
server glx version string: 1.4
server glx extensions:
    GLX_ARB_create_context, GLX_ARB_create_context_profile, 
    GLX_ARB_create_context_robustness, GLX_ARB_fbconfig_float, 
    GLX_ARB_framebuffer_sRGB, GLX_ARB_multisample, 
    GLX_EXT_create_context_es2_profile, GLX_EXT_create_context_es_profile, 
    GLX_EXT_fbconfig_packed_float, GLX_EXT_framebuffer_sRGB, 
    GLX_EXT_import_context, GLX_EXT_libglvnd, GLX_EXT_texture_from_pixmap, 
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_INTEL_swap_event, 
    GLX_MESA_copy_sub_buffer, GLX_OML_swap_method, GLX_SGIS_multisample, 
    GLX_SGIX_fbconfig, GLX_SGIX_pbuffer, GLX_SGIX_visual_select_group, 
    GLX_SGI_make_current_read, GLX_SGI_swap_control
client glx vendor string: Mesa Project and SGI
client glx version string: 1.4
client glx extensions:
    GLX_ARB_context_flush_control, GLX_ARB_create_context, 
    GLX_ARB_create_context_profile, GLX_ARB_create_context_robustness, 
    GLX_ARB_fbconfig_float, GLX_ARB_framebuffer_sRGB, 
    GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_buffer_age, 
    GLX_EXT_create_context_es2_profile, GLX_EXT_create_context_es_profile, 
    GLX_EXT_fbconfig_packed_float, GLX_EXT_framebuffer_sRGB, 
    GLX_EXT_import_context, GLX_EXT_texture_from_pixmap, GLX_EXT_visual_info, 
    GLX_EXT_visual_rating, GLX_INTEL_swap_event, GLX_MESA_copy_sub_buffer, 
    GLX_MESA_multithread_makecurrent, GLX_MESA_query_renderer, 
    GLX_MESA_swap_control, GLX_OML_swap_method, GLX_OML_sync_control, 
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer, 
    GLX_SGIX_visual_select_group, GLX_SGI_make_current_read, 
    GLX_SGI_swap_control, GLX_SGI_video_sync
GLX version: 1.4
GLX extensions:
    GLX_ARB_create_context, GLX_ARB_create_context_profile, 
    GLX_ARB_create_context_robustness, GLX_ARB_fbconfig_float, 
    GLX_ARB_framebuffer_sRGB, GLX_ARB_get_proc_address, GLX_ARB_multisample, 
    GLX_EXT_buffer_age, GLX_EXT_create_context_es2_profile, 
    GLX_EXT_create_context_es_profile, GLX_EXT_fbconfig_packed_float, 
    GLX_EXT_framebuffer_sRGB, GLX_EXT_import_context, GLX_EXT_visual_info, 
    GLX_EXT_visual_rating, GLX_INTEL_swap_event, GLX_MESA_copy_sub_buffer, 
    GLX_MESA_multithread_makecurrent, GLX_MESA_query_renderer, 
    GLX_MESA_swap_control, GLX_OML_swap_method, GLX_OML_sync_control, 
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer, 
    GLX_SGIX_visual_select_group, GLX_SGI_make_current_read, 
    GLX_SGI_swap_control, GLX_SGI_video_sync
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: X.Org (0x1002)
    Device: AMD Radeon HD 8600M Series (HAINAN / DRM 3.25.0 / 4.17.0-041700-generic, LLVM 6.0.0) (0x6660)
    Version: 18.0.0
    Accelerated: yes
    Video memory: 2047MB
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 4.5
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.1
Memory info (GL_ATI_meminfo):
    VBO free memory - total: 2046 MB, largest block: 2046 MB
    VBO free aux. memory - total: 3039 MB, largest block: 3039 MB
    Texture free memory - total: 2046 MB, largest block: 2046 MB
    Texture free aux. memory - total: 3039 MB, largest block: 3039 MB
    Renderbuffer free memory - total: 2046 MB, largest block: 2046 MB
    Renderbuffer free aux. memory - total: 3039 MB, largest block: 3039 MB
Memory info (GL_NVX_gpu_memory_info):
    Dedicated video memory: 2047 MB
    Total available memory: 5086 MB
    Currently available dedicated video memory: 2046 MB
OpenGL vendor string: X.Org
OpenGL renderer string: AMD Radeon HD 8600M Series (HAINAN / DRM 3.25.0 / 4.17.0-041700-generic, LLVM 6.0.0)
OpenGL core profile version string: 4.5 (Core Profile) Mesa 18.0.0-rc5
OpenGL core profile shading language version string: 4.50
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions: