Ubuntu-fr

borisb

Carte graphique HD4850 sur Ubuntu 20.04

Bonjour,

J'ai installé Ubuntu 20.04 sur un iMac de 2009 (12 GO de RAM, i5, HD4850).

L'installation s'est bien passée (en partie).

Par contre, j'ai été obligé de rajouter l'option "nomodeset" dans Grub pour arriver à démarrer.

Or cette option semble désactiver les pilotes de la carte graphique.

La carte graphique est reconnue :

lspci -nn | grep VGA
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] RV770/M98L [Mobility Radeon HD 4850] [1002:944a]

Par contre les drivers ne semblent pas bien installés :

glxinfo
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_context_flush_control, GLX_ARB_create_context,
    GLX_ARB_create_context_no_error, GLX_ARB_create_context_profile,
    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_no_config_context,
    GLX_EXT_texture_from_pixmap, GLX_EXT_visual_info, GLX_EXT_visual_rating,
    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
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_no_error, 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_context_flush_control, GLX_ARB_create_context,
    GLX_ARB_create_context_profile, GLX_ARB_fbconfig_float,
    GLX_ARB_framebuffer_sRGB, GLX_ARB_get_proc_address, 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_texture_from_pixmap, GLX_EXT_visual_info,
    GLX_EXT_visual_rating, GLX_MESA_copy_sub_buffer, GLX_MESA_query_renderer,
    GLX_OML_swap_method, GLX_SGIS_multisample, GLX_SGIX_fbconfig,
    GLX_SGIX_pbuffer, GLX_SGIX_visual_select_group, GLX_SGI_make_current_read
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: VMware, Inc. (0xffffffff)
    Device: llvmpipe (LLVM 9.0.1, 128 bits) (0xffffffff)
    Version: 20.1.0
    Accelerated: no
    Video memory: 11971MB
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 3.3
    Max compat profile version: 3.1
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.1
OpenGL vendor string: VMware, Inc.
OpenGL renderer string: llvmpipe (LLVM 9.0.1, 128 bits)
OpenGL core profile version string: 3.3 (Core Profile) Mesa 20.1.0-devel (git-b4cc116 2020-04-28 focal-oibaf-ppa)
OpenGL core profile shading language version string: 3.30
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
    GL_AMD_conservative_depth, GL_AMD_draw_buffers_blend,
    GL_AMD_gpu_shader_int64, GL_AMD_multi_draw_indirect,
    GL_AMD_query_buffer_object, GL_AMD_seamless_cubemap_per_texture,
    GL_AMD_shader_stencil_export, GL_AMD_shader_trinary_minmax,
    GL_AMD_texture_texture4, GL_AMD_vertex_shader_layer,
    GL_AMD_vertex_shader_viewport_index, GL_ANGLE_texture_compression_dxt3,
    GL_ANGLE_texture_compression_dxt5, GL_ARB_ES2_compatibility,
    GL_ARB_ES3_compatibility, GL_ARB_arrays_of_arrays, GL_ARB_base_instance,
    GL_ARB_blend_func_extended, GL_ARB_buffer_storage,
    GL_ARB_clear_buffer_object, GL_ARB_clear_texture, GL_ARB_clip_control,
    GL_ARB_compressed_texture_pixel_storage, GL_ARB_compute_shader,
    GL_ARB_conditional_render_inverted, GL_ARB_conservative_depth,
    GL_ARB_copy_buffer, GL_ARB_copy_image, GL_ARB_cull_distance,
    GL_ARB_debug_output, GL_ARB_depth_buffer_float, GL_ARB_depth_clamp,
    GL_ARB_derivative_control, GL_ARB_direct_state_access,
    GL_ARB_draw_buffers, GL_ARB_draw_buffers_blend,
    GL_ARB_draw_elements_base_vertex, GL_ARB_draw_indirect,
    GL_ARB_draw_instanced, GL_ARB_enhanced_layouts,
    GL_ARB_explicit_attrib_location, GL_ARB_explicit_uniform_location,
    GL_ARB_fragment_coord_conventions, GL_ARB_fragment_layer_viewport,
    GL_ARB_fragment_shader, GL_ARB_framebuffer_no_attachments,
    GL_ARB_framebuffer_object, GL_ARB_framebuffer_sRGB,
    GL_ARB_get_program_binary, GL_ARB_get_texture_sub_image,
    GL_ARB_gpu_shader_fp64, GL_ARB_gpu_shader_int64, GL_ARB_half_float_pixel,
    GL_ARB_half_float_vertex, GL_ARB_indirect_parameters,
    GL_ARB_instanced_arrays, GL_ARB_internalformat_query,
    GL_ARB_internalformat_query2, GL_ARB_invalidate_subdata,
    GL_ARB_map_buffer_alignment, GL_ARB_map_buffer_range, GL_ARB_multi_bind,
    GL_ARB_multi_draw_indirect, GL_ARB_occlusion_query2,
    GL_ARB_parallel_shader_compile, GL_ARB_pipeline_statistics_query,
    GL_ARB_pixel_buffer_object, GL_ARB_point_sprite,
    GL_ARB_polygon_offset_clamp, GL_ARB_program_interface_query,
    GL_ARB_provoking_vertex, GL_ARB_query_buffer_object, GL_ARB_robustness,
    GL_ARB_sampler_objects, GL_ARB_seamless_cube_map,
    GL_ARB_seamless_cubemap_per_texture, GL_ARB_separate_shader_objects,
    GL_ARB_shader_atomic_counter_ops, GL_ARB_shader_atomic_counters,
    GL_ARB_shader_bit_encoding, GL_ARB_shader_draw_parameters,
    GL_ARB_shader_group_vote, GL_ARB_shader_image_load_store,
    GL_ARB_shader_image_size, GL_ARB_shader_objects,
    GL_ARB_shader_stencil_export, GL_ARB_shader_storage_buffer_object,
    GL_ARB_shader_subroutine, GL_ARB_shader_texture_lod,
    GL_ARB_shading_language_420pack, GL_ARB_shading_language_include,
    GL_ARB_shading_language_packing, GL_ARB_stencil_texturing, GL_ARB_sync,
    GL_ARB_tessellation_shader, GL_ARB_texture_buffer_object,
    GL_ARB_texture_buffer_object_rgb32, GL_ARB_texture_buffer_range,
    GL_ARB_texture_compression_bptc, GL_ARB_texture_compression_rgtc,
    GL_ARB_texture_cube_map_array, GL_ARB_texture_float,
    GL_ARB_texture_gather, GL_ARB_texture_mirror_clamp_to_edge,
    GL_ARB_texture_multisample, GL_ARB_texture_non_power_of_two,
    GL_ARB_texture_query_levels, GL_ARB_texture_query_lod,
    GL_ARB_texture_rectangle, GL_ARB_texture_rg, GL_ARB_texture_rgb10_a2ui,
    GL_ARB_texture_stencil8, GL_ARB_texture_storage,
    GL_ARB_texture_storage_multisample, GL_ARB_texture_swizzle,
    GL_ARB_texture_view, GL_ARB_timer_query, GL_ARB_transform_feedback2,
    GL_ARB_transform_feedback3, GL_ARB_transform_feedback_instanced,
    GL_ARB_transform_feedback_overflow_query, GL_ARB_uniform_buffer_object,
    GL_ARB_vertex_array_bgra, GL_ARB_vertex_array_object,
    GL_ARB_vertex_attrib_64bit, GL_ARB_vertex_attrib_binding,
    GL_ARB_vertex_buffer_object, GL_ARB_vertex_shader,
    GL_ARB_vertex_type_10f_11f_11f_rev, GL_ARB_vertex_type_2_10_10_10_rev,
    GL_ARB_viewport_array, GL_ATI_blend_equation_separate,
    GL_ATI_texture_float, GL_ATI_texture_mirror_once,
    GL_EXT_EGL_image_storage, GL_EXT_EGL_sync, GL_EXT_abgr,
    GL_EXT_blend_equation_separate, GL_EXT_draw_buffers2,
    GL_EXT_draw_instanced, GL_EXT_framebuffer_blit,
    GL_EXT_framebuffer_multisample, GL_EXT_framebuffer_multisample_blit_scaled,
    GL_EXT_framebuffer_object, GL_EXT_framebuffer_sRGB,
    GL_EXT_packed_depth_stencil, GL_EXT_packed_float,
    GL_EXT_pixel_buffer_object, GL_EXT_polygon_offset_clamp,
    GL_EXT_provoking_vertex, GL_EXT_shader_integer_mix, GL_EXT_texture_array,
    GL_EXT_texture_compression_dxt1, GL_EXT_texture_compression_rgtc,
    GL_EXT_texture_compression_s3tc, GL_EXT_texture_integer,
    GL_EXT_texture_mirror_clamp, GL_EXT_texture_sRGB, GL_EXT_texture_sRGB_R8,
    GL_EXT_texture_sRGB_decode, GL_EXT_texture_shared_exponent,
    GL_EXT_texture_snorm, GL_EXT_texture_swizzle, GL_EXT_timer_query,
    GL_EXT_transform_feedback, GL_EXT_vertex_array_bgra,
    GL_EXT_vertex_attrib_64bit, GL_IBM_multimode_draw_arrays,
    GL_KHR_context_flush_control, GL_KHR_debug, GL_KHR_no_error,
    GL_KHR_parallel_shader_compile, GL_KHR_texture_compression_astc_ldr,
    GL_KHR_texture_compression_astc_sliced_3d, GL_MESA_pack_invert,
    GL_MESA_shader_integer_functions, GL_MESA_texture_signed_rgba,
    GL_MESA_ycbcr_texture, GL_NV_conditional_render, GL_NV_copy_image,
    GL_NV_depth_clamp, GL_NV_packed_depth_stencil, GL_OES_EGL_image,
    GL_S3_s3tc

OpenGL version string: 3.1 Mesa 20.1.0-devel (git-b4cc116 2020-04-28 focal-oibaf-ppa)
OpenGL shading language version string: 1.40
OpenGL context flags: (none)
OpenGL extensions:
    GL_AMD_conservative_depth, GL_AMD_draw_buffers_blend,
    GL_AMD_multi_draw_indirect, GL_AMD_query_buffer_object,
    GL_AMD_seamless_cubemap_per_texture, GL_AMD_shader_stencil_export,
    GL_AMD_shader_trinary_minmax, GL_AMD_texture_texture4,
    GL_ANGLE_texture_compression_dxt3, GL_ANGLE_texture_compression_dxt5,
    GL_APPLE_packed_pixels, GL_ARB_ES2_compatibility,
    GL_ARB_ES3_compatibility, GL_ARB_arrays_of_arrays, GL_ARB_base_instance,
    GL_ARB_blend_func_extended, GL_ARB_buffer_storage,
    GL_ARB_clear_buffer_object, GL_ARB_clear_texture, GL_ARB_clip_control,
    GL_ARB_color_buffer_float, GL_ARB_compatibility,
    GL_ARB_compressed_texture_pixel_storage, GL_ARB_compute_shader,
    GL_ARB_conditional_render_inverted, GL_ARB_conservative_depth,
    GL_ARB_copy_buffer, GL_ARB_copy_image, GL_ARB_cull_distance,
    GL_ARB_debug_output, GL_ARB_depth_buffer_float, GL_ARB_depth_clamp,
    GL_ARB_depth_texture, GL_ARB_derivative_control,
    GL_ARB_direct_state_access, GL_ARB_draw_buffers,
    GL_ARB_draw_buffers_blend, GL_ARB_draw_elements_base_vertex,
    GL_ARB_draw_indirect, GL_ARB_draw_instanced, GL_ARB_enhanced_layouts,
    GL_ARB_explicit_attrib_location, GL_ARB_explicit_uniform_location,
    GL_ARB_fragment_coord_conventions, GL_ARB_fragment_layer_viewport,
    GL_ARB_fragment_program, GL_ARB_fragment_program_shadow,
    GL_ARB_fragment_shader, GL_ARB_framebuffer_no_attachments,
    GL_ARB_framebuffer_object, GL_ARB_framebuffer_sRGB,
    GL_ARB_get_program_binary, GL_ARB_get_texture_sub_image,
    GL_ARB_half_float_pixel, GL_ARB_half_float_vertex,
    GL_ARB_indirect_parameters, GL_ARB_instanced_arrays,
    GL_ARB_internalformat_query, GL_ARB_internalformat_query2,
    GL_ARB_invalidate_subdata, GL_ARB_map_buffer_alignment,
    GL_ARB_map_buffer_range, GL_ARB_multi_bind, GL_ARB_multi_draw_indirect,
    GL_ARB_multisample, GL_ARB_multitexture, GL_ARB_occlusion_query,
    GL_ARB_occlusion_query2, GL_ARB_parallel_shader_compile,
    GL_ARB_pipeline_statistics_query, GL_ARB_pixel_buffer_object,
    GL_ARB_point_parameters, GL_ARB_point_sprite, GL_ARB_polygon_offset_clamp,
    GL_ARB_program_interface_query, GL_ARB_provoking_vertex,
    GL_ARB_query_buffer_object, GL_ARB_robustness, GL_ARB_sampler_objects,
    GL_ARB_seamless_cube_map, GL_ARB_seamless_cubemap_per_texture,
    GL_ARB_separate_shader_objects, GL_ARB_shader_atomic_counter_ops,
    GL_ARB_shader_atomic_counters, GL_ARB_shader_bit_encoding,
    GL_ARB_shader_draw_parameters, GL_ARB_shader_group_vote,
    GL_ARB_shader_image_load_store, GL_ARB_shader_image_size,
    GL_ARB_shader_objects, GL_ARB_shader_stencil_export,
    GL_ARB_shader_storage_buffer_object, GL_ARB_shader_subroutine,
    GL_ARB_shader_texture_lod, GL_ARB_shading_language_100,
    GL_ARB_shading_language_420pack, GL_ARB_shading_language_include,
    GL_ARB_shading_language_packing, GL_ARB_shadow, GL_ARB_stencil_texturing,
    GL_ARB_sync, GL_ARB_texture_border_clamp, GL_ARB_texture_buffer_object,
    GL_ARB_texture_buffer_object_rgb32, GL_ARB_texture_buffer_range,
    GL_ARB_texture_compression, GL_ARB_texture_compression_bptc,
    GL_ARB_texture_compression_rgtc, GL_ARB_texture_cube_map,
    GL_ARB_texture_cube_map_array, GL_ARB_texture_env_add,
    GL_ARB_texture_env_combine, GL_ARB_texture_env_crossbar,
    GL_ARB_texture_env_dot3, GL_ARB_texture_float, GL_ARB_texture_gather,
    GL_ARB_texture_mirror_clamp_to_edge, GL_ARB_texture_mirrored_repeat,
    GL_ARB_texture_multisample, GL_ARB_texture_non_power_of_two,
    GL_ARB_texture_query_levels, GL_ARB_texture_query_lod,
    GL_ARB_texture_rectangle, GL_ARB_texture_rg, GL_ARB_texture_rgb10_a2ui,
    GL_ARB_texture_stencil8, GL_ARB_texture_storage,
    GL_ARB_texture_storage_multisample, GL_ARB_texture_swizzle,
    GL_ARB_texture_view, GL_ARB_timer_query, GL_ARB_transform_feedback2,
    GL_ARB_transform_feedback3, GL_ARB_transform_feedback_instanced,
    GL_ARB_transform_feedback_overflow_query, GL_ARB_transpose_matrix,
    GL_ARB_uniform_buffer_object, GL_ARB_vertex_array_bgra,
    GL_ARB_vertex_array_object, GL_ARB_vertex_attrib_binding,
    GL_ARB_vertex_buffer_object, GL_ARB_vertex_program, GL_ARB_vertex_shader,
    GL_ARB_vertex_type_10f_11f_11f_rev, GL_ARB_vertex_type_2_10_10_10_rev,
    GL_ARB_viewport_array, GL_ARB_window_pos, GL_ATI_blend_equation_separate,
    GL_ATI_draw_buffers, GL_ATI_fragment_shader, GL_ATI_separate_stencil,
    GL_ATI_texture_compression_3dc, GL_ATI_texture_env_combine3,
    GL_ATI_texture_float, GL_ATI_texture_mirror_once,
    GL_EXT_EGL_image_storage, GL_EXT_EGL_sync, 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_direct_state_access, GL_EXT_draw_buffers2, GL_EXT_draw_instanced,
    GL_EXT_draw_range_elements, GL_EXT_fog_coord, GL_EXT_framebuffer_blit,
    GL_EXT_framebuffer_multisample, GL_EXT_framebuffer_multisample_blit_scaled,
    GL_EXT_framebuffer_object, GL_EXT_framebuffer_sRGB,
    GL_EXT_gpu_program_parameters, GL_EXT_gpu_shader4,
    GL_EXT_multi_draw_arrays, GL_EXT_packed_depth_stencil,
    GL_EXT_packed_float, GL_EXT_packed_pixels, GL_EXT_pixel_buffer_object,
    GL_EXT_point_parameters, GL_EXT_polygon_offset_clamp,
    GL_EXT_provoking_vertex, GL_EXT_rescale_normal, GL_EXT_secondary_color,
    GL_EXT_separate_specular_color, GL_EXT_shader_integer_mix,
    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_array, GL_EXT_texture_buffer_object,
    GL_EXT_texture_compression_dxt1, GL_EXT_texture_compression_latc,
    GL_EXT_texture_compression_rgtc, GL_EXT_texture_compression_s3tc,
    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_integer, GL_EXT_texture_lod_bias,
    GL_EXT_texture_mirror_clamp, GL_EXT_texture_object,
    GL_EXT_texture_rectangle, GL_EXT_texture_sRGB, GL_EXT_texture_sRGB_R8,
    GL_EXT_texture_sRGB_decode, GL_EXT_texture_shared_exponent,
    GL_EXT_texture_snorm, GL_EXT_texture_swizzle, GL_EXT_timer_query,
    GL_EXT_transform_feedback, GL_EXT_vertex_array, GL_EXT_vertex_array_bgra,
    GL_IBM_multimode_draw_arrays, GL_IBM_rasterpos_clip,
    GL_IBM_texture_mirrored_repeat, GL_INGR_blend_func_separate,
    GL_KHR_context_flush_control, GL_KHR_debug, GL_KHR_no_error,
    GL_KHR_parallel_shader_compile, GL_KHR_texture_compression_astc_ldr,
    GL_KHR_texture_compression_astc_sliced_3d, GL_MESA_pack_invert,
    GL_MESA_shader_integer_functions, GL_MESA_texture_signed_rgba,
    GL_MESA_window_pos, GL_MESA_ycbcr_texture, GL_NV_blend_square,
    GL_NV_conditional_render, GL_NV_copy_image, GL_NV_depth_clamp,
    GL_NV_fog_distance, GL_NV_light_max_exponent, GL_NV_packed_depth_stencil,
    GL_NV_primitive_restart, 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

OpenGL ES profile version string: OpenGL ES 3.1 Mesa 20.1.0-devel (git-b4cc116 2020-04-28 focal-oibaf-ppa)
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.10
OpenGL ES profile extensions:
    GL_ANGLE_texture_compression_dxt3, GL_ANGLE_texture_compression_dxt5,
    GL_APPLE_texture_max_level, GL_EXT_EGL_image_storage,
    GL_EXT_base_instance, GL_EXT_blend_func_extended, GL_EXT_blend_minmax,
    GL_EXT_buffer_storage, GL_EXT_clip_control, GL_EXT_clip_cull_distance,
    GL_EXT_color_buffer_float, GL_EXT_compressed_ETC1_RGB8_sub_texture,
    GL_EXT_copy_image, GL_EXT_depth_clamp, GL_EXT_discard_framebuffer,
    GL_EXT_disjoint_timer_query, GL_EXT_draw_buffers,
    GL_EXT_draw_buffers_indexed, GL_EXT_draw_elements_base_vertex,
    GL_EXT_draw_instanced, GL_EXT_float_blend, GL_EXT_frag_depth,
    GL_EXT_map_buffer_range, GL_EXT_multi_draw_arrays,
    GL_EXT_occlusion_query_boolean, GL_EXT_polygon_offset_clamp,
    GL_EXT_read_format_bgra, GL_EXT_render_snorm, GL_EXT_sRGB_write_control,
    GL_EXT_separate_shader_objects, GL_EXT_shader_implicit_conversions,
    GL_EXT_shader_integer_mix, GL_EXT_shader_io_blocks,
    GL_EXT_tessellation_point_size, GL_EXT_tessellation_shader,
    GL_EXT_texture_border_clamp, GL_EXT_texture_buffer,
    GL_EXT_texture_compression_bptc, GL_EXT_texture_compression_dxt1,
    GL_EXT_texture_compression_rgtc, GL_EXT_texture_compression_s3tc,
    GL_EXT_texture_compression_s3tc_srgb, GL_EXT_texture_format_BGRA8888,
    GL_EXT_texture_norm16, GL_EXT_texture_query_lod, GL_EXT_texture_rg,
    GL_EXT_texture_sRGB_R8, GL_EXT_texture_sRGB_decode,
    GL_EXT_texture_type_2_10_10_10_REV, GL_EXT_texture_view,
    GL_EXT_unpack_subimage, GL_KHR_context_flush_control, GL_KHR_debug,
    GL_KHR_no_error, GL_KHR_parallel_shader_compile,
    GL_KHR_texture_compression_astc_ldr,
    GL_KHR_texture_compression_astc_sliced_3d, GL_MESA_framebuffer_flip_y,
    GL_MESA_shader_integer_functions, GL_NV_conditional_render,
    GL_NV_draw_buffers, GL_NV_fbo_color_attachments, GL_NV_image_formats,
    GL_NV_pixel_buffer_object, GL_NV_read_buffer, GL_NV_read_depth,
    GL_NV_read_depth_stencil, GL_NV_read_stencil, GL_OES_EGL_image,
    GL_OES_EGL_image_external, GL_OES_EGL_image_external_essl3,
    GL_OES_EGL_sync, GL_OES_compressed_ETC1_RGB8_texture, GL_OES_copy_image,
    GL_OES_depth24, GL_OES_depth_texture, GL_OES_depth_texture_cube_map,
    GL_OES_draw_buffers_indexed, GL_OES_draw_elements_base_vertex,
    GL_OES_element_index_uint, GL_OES_fbo_render_mipmap,
    GL_OES_get_program_binary, GL_OES_mapbuffer, GL_OES_packed_depth_stencil,
    GL_OES_required_internalformat, GL_OES_rgb8_rgba8,
    GL_OES_shader_image_atomic, GL_OES_shader_io_blocks,
    GL_OES_standard_derivatives, GL_OES_stencil8, GL_OES_surfaceless_context,
    GL_OES_tessellation_point_size, GL_OES_tessellation_shader,
    GL_OES_texture_3D, GL_OES_texture_border_clamp, GL_OES_texture_buffer,
    GL_OES_texture_float, GL_OES_texture_float_linear,
    GL_OES_texture_half_float, GL_OES_texture_half_float_linear,
    GL_OES_texture_npot, GL_OES_texture_stencil8,
    GL_OES_texture_storage_multisample_2d_array, GL_OES_texture_view,
    GL_OES_vertex_array_object, GL_OES_vertex_half_float

J'ai modifié le fichier Xorg.conf dans /etc/X11/xorg.conf.d/20-amdgpu.conf

Section "Device"
     Identifier "AMD"
     Driver "amdgpu"
EndSection

La définition de l'écran est bonne (2560 * 1440) mais je perds des images dans les vidéos (quasiment 1 sur 2 avec VLC).

J'ai lu plusieurs fois les pages radeon, mais je n'arrive pas à m'en sortir.

Et si je supprime l'option "nomodeset" de Grub, j'obtiens un écran noir après le démarrage.

abelthorne

Re : Carte graphique HD4850 sur Ubuntu 20.04

Ton GPU ne va pas supporter le pilote amdgpu, il ne gère que des modèles relativement récents. Dans ton xorg.conf (ou un fichier dans xorg.conf.d comme ton 20-amdgpu.conf), essaie le pilote radeonsi ou radeon tout court − ce dernier étant censé détecter le bon et retomber sur radeonsi dans ton cas.

borisb

Re : Carte graphique HD4850 sur Ubuntu 20.04

Ok. Merci beaucoup pour ta réponse.

Je ne change donc que le fichier 20-amdgpu.conf.

J'essaie ça rapidement.