WebGL doesn't work after update

Question

When I updated from kernel 3.6.9 to 3.8.1 (after pacman -Syu), WebGL didn't work anymore. Now I updated to 3.9.6, but the problem persists.
WebGL correctly worked both in Chromium and Firefox, but now their createContext returns null with "webgl" and "experimental-webgl" (Firefox says "Error: WebGL: Can't get a usable WebGL context").
Also I can't create a context with OpenGL version >1.4 with GLFW.
PS: I don't use precompiled kernels from the official repository, because they don't work with NDISwrapper.
glxinfo:
name of display: :0.0
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_multisample, GLX_EXT_create_context_es2_profile,
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_OML_swap_method, GLX_SGIS_multisample, GLX_SGIX_fbconfig,
GLX_SGIX_pbuffer, GLX_SGIX_visual_select_group, GLX_SGI_swap_control
client glx vendor string: Mesa Project and SGI
client glx version string: 1.4
client glx extensions:
GLX_ARB_create_context, GLX_ARB_create_context_profile,
GLX_ARB_create_context_robustness, GLX_ARB_framebuffer_sRGB,
GLX_ARB_get_proc_address, GLX_ARB_multisample,
GLX_EXT_create_context_es2_profile, 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_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_get_proc_address, GLX_ARB_multisample,
GLX_EXT_create_context_es2_profile, 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_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
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) G33
OpenGL version string: 1.4 Mesa 9.1.3
OpenGL extensions:
GL_3DFX_texture_compression_FXT1, GL_ANGLE_texture_compression_dxt3,
GL_ANGLE_texture_compression_dxt5, GL_APPLE_object_purgeable,
GL_APPLE_packed_pixels, GL_APPLE_vertex_array_object,
GL_ARB_ES2_compatibility, GL_ARB_copy_buffer, GL_ARB_debug_output,
GL_ARB_depth_texture, GL_ARB_draw_buffers,
GL_ARB_draw_elements_base_vertex, GL_ARB_explicit_attrib_location,
GL_ARB_fragment_program, GL_ARB_fragment_shader,
GL_ARB_framebuffer_object, GL_ARB_get_program_binary,
GL_ARB_half_float_pixel, GL_ARB_internalformat_query,
GL_ARB_invalidate_subdata, GL_ARB_map_buffer_range, GL_ARB_multisample,
GL_ARB_multitexture, GL_ARB_pixel_buffer_object, GL_ARB_point_parameters,
GL_ARB_point_sprite, GL_ARB_provoking_vertex, GL_ARB_robustness,
GL_ARB_sampler_objects, GL_ARB_shader_objects,
GL_ARB_shading_language_100, GL_ARB_shadow, GL_ARB_sync,
GL_ARB_texture_border_clamp, GL_ARB_texture_compression,
GL_ARB_texture_cube_map, GL_ARB_texture_env_add,
GL_ARB_texture_env_combine, GL_ARB_texture_env_crossbar,
GL_ARB_texture_env_dot3, GL_ARB_texture_mirrored_repeat,
GL_ARB_texture_non_power_of_two, GL_ARB_texture_rectangle,
GL_ARB_texture_storage, GL_ARB_transpose_matrix,
GL_ARB_vertex_array_object, GL_ARB_vertex_buffer_object,
GL_ARB_vertex_program, GL_ARB_vertex_shader, GL_ARB_window_pos,
GL_ATI_blend_equation_separate, GL_ATI_draw_buffers,
GL_ATI_separate_stencil, GL_ATI_texture_env_combine3, GL_EXT_abgr,
GL_EXT_bgra, GL_EXT_blend_color, GL_EXT_blend_equation_separate,
GL_EXT_blend_func_separate, GL_EXT_blend_minmax, GL_EXT_blend_subtract,
GL_EXT_compiled_vertex_array, GL_EXT_copy_texture,
GL_EXT_draw_range_elements, GL_EXT_fog_coord, GL_EXT_framebuffer_blit,
GL_EXT_framebuffer_multisample, GL_EXT_framebuffer_object,
GL_EXT_gpu_program_parameters, GL_EXT_multi_draw_arrays,
GL_EXT_packed_depth_stencil, GL_EXT_packed_pixels,
GL_EXT_pixel_buffer_object, GL_EXT_point_parameters,
GL_EXT_polygon_offset, GL_EXT_provoking_vertex, GL_EXT_rescale_normal,
GL_EXT_secondary_color, GL_EXT_separate_shader_objects,
GL_EXT_separate_specular_color, GL_EXT_shadow_funcs,
GL_EXT_stencil_two_side, GL_EXT_stencil_wrap, GL_EXT_subtexture,
GL_EXT_texture, GL_EXT_texture3D, GL_EXT_texture_compression_dxt1,
GL_EXT_texture_cube_map, GL_EXT_texture_edge_clamp,
GL_EXT_texture_env_add, GL_EXT_texture_env_combine,
GL_EXT_texture_env_dot3, GL_EXT_texture_filter_anisotropic,
GL_EXT_texture_lod_bias, GL_EXT_texture_object, GL_EXT_texture_rectangle,
GL_EXT_vertex_array, GL_IBM_multimode_draw_arrays, GL_IBM_rasterpos_clip,
GL_IBM_texture_mirrored_repeat, GL_INGR_blend_func_separate,
GL_MESA_pack_invert, GL_MESA_window_pos, GL_MESA_ycbcr_texture,
GL_NV_blend_square, GL_NV_light_max_exponent, GL_NV_packed_depth_stencil,
GL_NV_texgen_reflection, GL_NV_texture_env_combine4,
GL_NV_texture_rectangle, GL_OES_EGL_image, GL_OES_read_format,
GL_S3_s3tc, GL_SGIS_generate_mipmap, GL_SGIS_texture_border_clamp,
GL_SGIS_texture_edge_clamp, GL_SGIS_texture_lod, GL_SUN_multi_draw_arrays
chrome://gpu
Graphics Feature Status
Canvas: Hardware accelerated
Compositing: Hardware accelerated
3D CSS: Hardware accelerated
CSS Animation: Accelerated
WebGL: Hardware accelerated
WebGL multisampling: Hardware accelerated
Flash 3D: Hardware accelerated
Flash Stage3D: Hardware accelerated
Flash Stage3D Baseline profile: Hardware accelerated
Texture Sharing: Hardware accelerated
Video Decode: Hardware accelerated
Video: Hardware accelerated
Panel Fitting: Unavailable. Hardware acceleration disabled.
Rasterization: Software only. Hardware acceleration disabled.
Problems Detected
Panel fitting is unavailable, either disabled at the command line or not supported by the current system.
Force compositing mode is off, either disabled at the command line or not supported by the current system.
Accelerated rasterization has not been enabled or is not supported by the current system.
Version Information
Data exported 21/6/2013 10:43:04
Chrome version Chrome/27.0.1453.110
Operating system Linux 3.9.6
Software rendering list version 0
ANGLE revision 2042
2D graphics backend Skia
Driver Information
Initialization time 99
Sandboxed true
GPU0 VENDOR = 0x8086 [Intel Corporation], DEVICE= 0x29c2 [82G33/G31 Express Integrated Graphics Controller]
Optimus false
AMD switchable false
Driver vendor Mesa
Driver version 9.1.3
Driver date
Pixel shader version
Vertex shader version
Machine model
GL version 1.4
GL_VENDOR Intel Open Source Technology Center
GL_RENDERER Mesa DRI Intel(R) G33
GL_VERSION 1.4 Mesa 9.1.3
GL_EXTENSIONS GL_ARB_depth_texture GL_ARB_draw_buffers GL_ARB_fragment_program GL_ARB_multisample GL_ARB_multitexture GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_shadow GL_ARB_texture_border_clamp GL_ARB_texture_compression GL_ARB_texture_cube_map GL_ARB_texture_env_add GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar GL_ARB_texture_env_dot3 GL_ARB_texture_mirrored_repeat GL_ARB_texture_non_power_of_two GL_ARB_texture_rectangle GL_ARB_transpose_matrix GL_ARB_vertex_program GL_ARB_window_pos GL_EXT_abgr GL_EXT_bgra GL_EXT_blend_color GL_EXT_blend_equation_separate GL_EXT_blend_func_separate GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_copy_texture GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_object GL_EXT_multi_draw_arrays GL_EXT_packed_pixels GL_EXT_point_parameters GL_EXT_polygon_offset GL_EXT_rescale_normal GL_EXT_secondary_color GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_two_side GL_EXT_stencil_wrap GL_EXT_subtexture GL_EXT_texture GL_EXT_texture3D GL_EXT_texture_compression_dxt1 GL_EXT_texture_edge_clamp GL_EXT_texture_env_add GL_EXT_texture_env_combine GL_EXT_texture_env_dot3 GL_EXT_texture_filter_anisotropic GL_EXT_texture_lod_bias GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_vertex_array GL_3DFX_texture_compression_FXT1 GL_APPLE_packed_pixels GL_ATI_draw_buffers GL_ATI_texture_env_combine3 GL_ATIX_texture_env_combine3 GL_IBM_texture_mirrored_repeat GL_INGR_blend_func_separate GL_MESA_pack_invert GL_MESA_ycbcr_texture GL_NV_blend_square GL_NV_light_max_exponent GL_NV_texgen_reflection GL_NV_texture_env_combine4 GL_NV_texture_rectangle GL_SGIS_generate_mipmap GL_SGIS_texture_border_clamp GL_SGIS_texture_edge_clamp GL_SGIS_texture_lod GL_SUN_multi_draw_arrays
Log Messages
[30720:30720:0621/082730:ERROR:context_group.cc(140)] : ContextGroup::Initialize failed because too few texture units supported.
[30720:30720:0621/082730:ERROR:gles2_cmd_decoder.cc(2310)] : GpuScheduler::InitializeCommon failed because group failed to initialize.
[30720:30720:0621/083440:ERROR:context_group.cc(140)] : ContextGroup::Initialize failed because too few texture units supported.
[30720:30720:0621/083440:ERROR:gles2_cmd_decoder.cc(2310)] : GpuScheduler::InitializeCommon failed because group failed to initialize.
[30720:30720:0621/084217:ERROR:context_group.cc(140)] : ContextGroup::Initialize failed because too few texture units supported.
[30720:30720:0621/084217:ERROR:gles2_cmd_decoder.cc(2310)] : GpuScheduler::InitializeCommon failed because group failed to initialize.
[30720:30720:0621/084217:ERROR:context_group.cc(140)] : ContextGroup::Initialize failed because too few texture units supported.
[30720:30720:0621/084217:ERROR:gles2_cmd_decoder.cc(2310)] : GpuScheduler::InitializeCommon failed because group failed to initialize.

Answer 1

Hi Berclaz74,
If you are having issues with your Thunderbolt external monitor after a software update, you may want to try the troubleshooting in the following article, in particular the step about resetting the PRAM and SMC.
Apple computers: Troubleshooting issues with video on internal or external displays
http://support.apple.com/kb/ht1573
Cheers,
- Brenden