docs/envvars.rst

   1 Environment Variables
   2 =====================
   3
   4 Normally, no environment variables need to be set. Most of the
   5 environment variables used by Mesa/Gallium are for debugging purposes,
   6 but they can sometimes be useful for debugging end-user issues.
   7
   8 LibGL environment variables
   9 ---------------------------
  10
  11 ``LIBGL_DEBUG``
  12    If defined debug information will be printed to stderr. If set to
  13    ``verbose`` additional information will be printed.
  14 ``LIBGL_DRIVERS_PATH``
  15    colon-separated list of paths to search for DRI drivers
  16 ``LIBGL_ALWAYS_INDIRECT``
  17    if set to ``true``, forces an indirect rendering context/connection.
  18 ``LIBGL_ALWAYS_SOFTWARE``
  19    if set to ``true``, always use software rendering
  20 ``LIBGL_NO_DRAWARRAYS``
  21    if set to ``true``, do not use DrawArrays GLX protocol (for
  22    debugging)
  23 ``LIBGL_SHOW_FPS``
  24    print framerate to stdout based on the number of ``glXSwapBuffers``
  25    calls per second.
  26 ``LIBGL_DRI3_DISABLE``
  27    disable DRI3 if set to ``true``.
  28
  29 Core Mesa environment variables
  30 -------------------------------
  31
  32 ``MESA_NO_ASM``
  33    if set, disables all assembly language optimizations
  34 ``MESA_NO_MMX``
  35    if set, disables Intel MMX optimizations
  36 ``MESA_NO_3DNOW``
  37    if set, disables AMD 3DNow! optimizations
  38 ``MESA_NO_SSE``
  39    if set, disables Intel SSE optimizations
  40 ``MESA_NO_ERROR``
  41    if set to 1, error checking is disabled as per ``KHR_no_error``. This
  42    will result in undefined behaviour for invalid use of the api, but
  43    can reduce CPU use for apps that are known to be error free.
  44 ``MESA_DEBUG``
  45    if set, error messages are printed to stderr. For example, if the
  46    application generates a ``GL_INVALID_ENUM`` error, a corresponding
  47    error message indicating where the error occurred, and possibly why,
  48    will be printed to stderr. For release builds, ``MESA_DEBUG``
  49    defaults to off (no debug output). ``MESA_DEBUG`` accepts the
  50    following comma-separated list of named flags, which adds extra
  51    behaviour to just set ``MESA_DEBUG=1``:
  52
  53    ``silent``
  54       turn off debug messages. Only useful for debug builds.
  55    ``flush``
  56       flush after each drawing command
  57    ``incomplete_tex``
  58       extra debug messages when a texture is incomplete
  59    ``incomplete_fbo``
  60       extra debug messages when a fbo is incomplete
  61    ``context``
  62       create a debug context (see ``GLX_CONTEXT_DEBUG_BIT_ARB``) and
  63       print error and performance messages to stderr (or
  64       ``MESA_LOG_FILE``).
  65
  66 ``MESA_LOG_FILE``
  67    specifies a file name for logging all errors, warnings, etc., rather
  68    than stderr
  69 ``MESA_TEX_PROG``
  70    if set, implement conventional texture env modes with fragment
  71    programs (intended for developers only)
  72 ``MESA_TNL_PROG``
  73    if set, implement conventional vertex transformation operations with
  74    vertex programs (intended for developers only). Setting this variable
  75    automatically sets the ``MESA_TEX_PROG`` variable as well.
  76 ``MESA_EXTENSION_OVERRIDE``
  77    can be used to enable/disable extensions. A value such as
  78    ``GL_EXT_foo -GL_EXT_bar`` will enable the ``GL_EXT_foo`` extension
  79    and disable the ``GL_EXT_bar`` extension.
  80 ``MESA_EXTENSION_MAX_YEAR``
  81    The ``GL_EXTENSIONS`` string returned by Mesa is sorted by extension
  82    year. If this variable is set to year X, only extensions defined on
  83    or before year X will be reported. This is to work-around a bug in
  84    some games where the extension string is copied into a fixed-size
  85    buffer without truncating. If the extension string is too long, the
  86    buffer overrun can cause the game to crash. This is a work-around for
  87    that.
  88 ``MESA_GL_VERSION_OVERRIDE``
  89    changes the value returned by ``glGetString(GL_VERSION)`` and
  90    possibly the GL API type.
  91
  92    -  The format should be ``MAJOR.MINOR[FC|COMPAT]``
  93    -  ``FC`` is an optional suffix that indicates a forward compatible
  94       context. This is only valid for versions >= 3.0.
  95    -  ``COMPAT`` is an optional suffix that indicates a compatibility
  96       context or ``GL_ARB_compatibility`` support. This is only valid
  97       for versions >= 3.1.
  98    -  GL versions <= 3.0 are set to a compatibility (non-Core) profile
  99    -  GL versions = 3.1, depending on the driver, it may or may not have
 100       the ``ARB_compatibility`` extension enabled.
 101    -  GL versions >= 3.2 are set to a Core profile
 102    -  Examples:
 103
 104       ``2.1``
 105          select a compatibility (non-Core) profile with GL version 2.1.
 106       ``3.0``
 107          select a compatibility (non-Core) profile with GL version 3.0.
 108       ``3.0FC``
 109          select a Core+Forward Compatible profile with GL version 3.0.
 110       ``3.1``
 111          select GL version 3.1 with ``GL_ARB_compatibility`` enabled per
 112          the driver default.
 113       ``3.1FC``
 114          select GL version 3.1 with forward compatibility and
 115          ``GL_ARB_compatibility`` disabled.
 116       ``3.1COMPAT``
 117          select GL version 3.1 with ``GL_ARB_compatibility`` enabled.
 118       ``X.Y``
 119          override GL version to X.Y without changing the profile.
 120       ``X.YFC``
 121          select a Core+Forward Compatible profile with GL version X.Y.
 122       ``X.YCOMPAT``
 123          select a Compatibility profile with GL version X.Y.
 124
 125    -  Mesa may not really implement all the features of the given
 126       version. (for developers only)
 127
 128 ``MESA_GLES_VERSION_OVERRIDE``
 129    changes the value returned by ``glGetString(GL_VERSION)`` for OpenGL
 130    ES.
 131
 132    -  The format should be ``MAJOR.MINOR``
 133    -  Examples: ``2.0``, ``3.0``, ``3.1``
 134    -  Mesa may not really implement all the features of the given
 135       version. (for developers only)
 136
 137 ``MESA_GLSL_VERSION_OVERRIDE``
 138    changes the value returned by
 139    ``glGetString(GL_SHADING_LANGUAGE_VERSION)``. Valid values are
 140    integers, such as ``130``. Mesa will not really implement all the
 141    features of the given language version if it's higher than what's
 142    normally reported. (for developers only)
 143 ``MESA_GLSL_CACHE_DISABLE``
 144    if set to ``true``, disables the GLSL shader cache
 145 ``MESA_GLSL_CACHE_MAX_SIZE``
 146    if set, determines the maximum size of the on-disk cache of compiled
 147    GLSL programs. Should be set to a number optionally followed by
 148    ``K``, ``M``, or ``G`` to specify a size in kilobytes, megabytes, or
 149    gigabytes. By default, gigabytes will be assumed. And if unset, a
 150    maximum size of 1GB will be used.
 151
 152    .. note::
 153
 154       A separate cache might be created for each architecture that Mesa is
 155       installed for on your system. For example under the default settings
 156       you may end up with a 1GB cache for x86_64 and another 1GB cache for
 157       i386.
 158
 159 ``MESA_GLSL_CACHE_DIR``
 160    if set, determines the directory to be used for the on-disk cache of
 161    compiled GLSL programs. If this variable is not set, then the cache
 162    will be stored in ``$XDG_CACHE_HOME/mesa_shader_cache`` (if that
 163    variable is set), or else within ``.cache/mesa_shader_cache`` within
 164    the user's home directory.
 165 ``MESA_GLSL``
 166    :ref:`shading language compiler options <envvars>`
 167 ``MESA_NO_MINMAX_CACHE``
 168    when set, the minmax index cache is globally disabled.
 169 ``MESA_SHADER_CAPTURE_PATH``
 170    see :ref:`Capturing Shaders <capture>`
 171 ``MESA_SHADER_DUMP_PATH`` and ``MESA_SHADER_READ_PATH``
 172    see :ref:`Experimenting with Shader
 173    Replacements <replacement>`
 174 ``MESA_VK_VERSION_OVERRIDE``
 175    changes the Vulkan physical device version as returned in
 176    ``VkPhysicalDeviceProperties::apiVersion``.
 177
 178    -  The format should be ``MAJOR.MINOR[.PATCH]``
 179    -  This will not let you force a version higher than the driver's
 180       instance version as advertised by ``vkEnumerateInstanceVersion``
 181    -  This can be very useful for debugging but some features may not be
 182       implemented correctly. (For developers only)
 183
 184 NIR passes enviroment variables
 185 -------------------------------
 186
 187 The following are only applicable for drivers that uses NIR, as they
 188 modify the behaviour for the common NIR_PASS and NIR_PASS_V macros, that
 189 wrap calls to NIR lowering/optimizations.
 190
 191 ``NIR_PRINT``
 192    If defined, the resulting NIR shader will be printed out at each
 193    succesful NIR lowering/optimization call.
 194 ``NIR_TEST_CLONE``
 195    If defined, cloning a NIR shader would be tested at each succesful
 196    NIR lowering/optimization call.
 197 ``NIR_TEST_SERIALIZE``
 198    If defined, serialize and deserialize a NIR shader would be tested at
 199    each succesful NIR lowering/optimization call.
 200
 201 Mesa Xlib driver environment variables
 202 --------------------------------------
 203
 204 The following are only applicable to the Mesa Xlib software driver. See
 205 the :doc:`Xlib software driver page <xlibdriver>` for details.
 206
 207 ``MESA_RGB_VISUAL``
 208    specifies the X visual and depth for RGB mode
 209 ``MESA_CI_VISUAL``
 210    specifies the X visual and depth for CI mode
 211 ``MESA_BACK_BUFFER``
 212    specifies how to implement the back color buffer, either ``pixmap``
 213    or ``ximage``
 214 ``MESA_GAMMA``
 215    gamma correction coefficients for red, green, blue channels
 216 ``MESA_XSYNC``
 217    enable synchronous X behavior (for debugging only)
 218 ``MESA_GLX_FORCE_CI``
 219    if set, force GLX to treat 8bpp visuals as CI visuals
 220 ``MESA_GLX_FORCE_ALPHA``
 221    if set, forces RGB windows to have an alpha channel.
 222 ``MESA_GLX_DEPTH_BITS``
 223    specifies default number of bits for depth buffer.
 224 ``MESA_GLX_ALPHA_BITS``
 225    specifies default number of bits for alpha channel.
 226
 227 i945/i965 driver environment variables (non-Gallium)
 228 ----------------------------------------------------
 229
 230 ``INTEL_NO_HW``
 231    if set to 1, prevents batches from being submitted to the hardware.
 232    This is useful for debugging hangs, etc.
 233 ``INTEL_DEBUG``
 234    a comma-separated list of named flags, which do various things:
 235
 236    ``ann``
 237       annotate IR in assembly dumps
 238    ``aub``
 239       dump batches into an AUB trace for use with simulation tools
 240    ``bat``
 241       emit batch information
 242    ``blit``
 243       emit messages about blit operations
 244    ``blorp``
 245       emit messages about the blorp operations (blits & clears)
 246    ``buf``
 247       emit messages about buffer objects
 248    ``clip``
 249       emit messages about the clip unit (for old gens, includes the CLIP
 250       program)
 251    ``color``
 252       use color in output
 253    ``cs``
 254       dump shader assembly for compute shaders
 255    ``do32``
 256       generate compute shader SIMD32 programs even if workgroup size
 257       doesn't exceed the SIMD16 limit
 258    ``dri``
 259       emit messages about the DRI interface
 260    ``fbo``
 261       emit messages about framebuffers
 262    ``fs``
 263       dump shader assembly for fragment shaders
 264    ``gs``
 265       dump shader assembly for geometry shaders
 266    ``hex``
 267       print instruction hex dump with the disassembly
 268    ``l3``
 269       emit messages about the new L3 state during transitions
 270    ``miptree``
 271       emit messages about miptrees
 272    ``no8``
 273       don't generate SIMD8 fragment shader
 274    ``no16``
 275       suppress generation of 16-wide fragment shaders. useful for
 276       debugging broken shaders
 277    ``nocompact``
 278       disable instruction compaction
 279    ``nodualobj``
 280       suppress generation of dual-object geometry shader code
 281    ``nofc``
 282       disable fast clears
 283    ``norbc``
 284       disable single sampled render buffer compression
 285    ``optimizer``
 286       dump shader assembly to files at each optimization pass and
 287       iteration that make progress
 288    ``perf``
 289       emit messages about performance issues
 290    ``perfmon``
 291       emit messages about ``AMD_performance_monitor``
 292    ``pix``
 293       emit messages about pixel operations
 294    ``prim``
 295       emit messages about drawing primitives
 296    ``reemit``
 297       mark all state dirty on each draw call
 298    ``sf``
 299       emit messages about the strips & fans unit (for old gens, includes
 300       the SF program)
 301    ``shader_time``
 302       record how much GPU time is spent in each shader
 303    ``spill_fs``
 304       force spilling of all registers in the scalar backend (useful to
 305       debug spilling code)
 306    ``spill_vec4``
 307       force spilling of all registers in the vec4 backend (useful to
 308       debug spilling code)
 309    ``state``
 310       emit messages about state flag tracking
 311    ``submit``
 312       emit batchbuffer usage statistics
 313    ``sync``
 314       after sending each batch, emit a message and wait for that batch
 315       to finish rendering
 316    ``tcs``
 317       dump shader assembly for tessellation control shaders
 318    ``tes``
 319       dump shader assembly for tessellation evaluation shaders
 320    ``tex``
 321       emit messages about textures.
 322    ``urb``
 323       emit messages about URB setup
 324    ``vert``
 325       emit messages about vertex assembly
 326    ``vs``
 327       dump shader assembly for vertex shaders
 328
 329 ``INTEL_SCALAR_VS`` (or ``TCS``, ``TES``, ``GS``)
 330    force scalar/vec4 mode for a shader stage (Gen8-9 only)
 331 ``INTEL_PRECISE_TRIG``
 332    if set to 1, true or yes, then the driver prefers accuracy over
 333    performance in trig functions.
 334
 335 Radeon driver environment variables (radeon, r200, and r300g)
 336 -------------------------------------------------------------
 337
 338 ``RADEON_NO_TCL``
 339    if set, disable hardware-accelerated Transform/Clip/Lighting.
 340
 341 EGL environment variables
 342 -------------------------
 343
 344 Mesa EGL supports different sets of environment variables. See the
 345 :doc:`Mesa EGL <egl>` page for the details.
 346
 347 Gallium environment variables
 348 -----------------------------
 349
 350 ``GALLIUM_HUD``
 351    draws various information on the screen, like framerate, cpu load,
 352    driver statistics, performance counters, etc. Set
 353    ``GALLIUM_HUD=help`` and run e.g. ``glxgears`` for more info.
 354 ``GALLIUM_HUD_PERIOD``
 355    sets the hud update rate in seconds (float). Use zero to update every
 356    frame. The default period is 1/2 second.
 357 ``GALLIUM_HUD_VISIBLE``
 358    control default visibility, defaults to true.
 359 ``GALLIUM_HUD_TOGGLE_SIGNAL``
 360    toggle visibility via user specified signal. Especially useful to
 361    toggle hud at specific points of application and disable for
 362    unencumbered viewing the rest of the time. For example, set
 363    ``GALLIUM_HUD_VISIBLE`` to ``false`` and
 364    ``GALLIUM_HUD_TOGGLE_SIGNAL`` to ``10`` (``SIGUSR1``). Use
 365    ``kill -10 <pid>`` to toggle the hud as desired.
 366 ``GALLIUM_HUD_SCALE``
 367    Scale hud by an integer factor, for high DPI displays. Default is 1.
 368 ``GALLIUM_HUD_DUMP_DIR``
 369    specifies a directory for writing the displayed hud values into
 370    files.
 371 ``GALLIUM_DRIVER``
 372    useful in combination with ``LIBGL_ALWAYS_SOFTWARE=true`` for
 373    choosing one of the software renderers ``softpipe``, ``llvmpipe`` or
 374    ``swr``.
 375 ``GALLIUM_LOG_FILE``
 376    specifies a file for logging all errors, warnings, etc. rather than
 377    stderr.
 378 ``GALLIUM_PRINT_OPTIONS``
 379    if non-zero, print all the Gallium environment variables which are
 380    used, and their current values.
 381 ``GALLIUM_DUMP_CPU``
 382    if non-zero, print information about the CPU on start-up
 383 ``TGSI_PRINT_SANITY``
 384    if set, do extra sanity checking on TGSI shaders and print any errors
 385    to stderr.
 386 ``DRAW_FSE``
 387    ???
 388 ``DRAW_NO_FSE``
 389    ???
 390 ``DRAW_USE_LLVM``
 391    if set to zero, the draw module will not use LLVM to execute shaders,
 392    vertex fetch, etc.
 393 ``ST_DEBUG``
 394    controls debug output from the Mesa/Gallium state tracker. Setting to
 395    ``tgsi``, for example, will print all the TGSI shaders. See
 396    ``src/mesa/state_tracker/st_debug.c`` for other options.
 397
 398 Clover environment variables
 399 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 400
 401 ``CLOVER_EXTRA_BUILD_OPTIONS``
 402    allows specifying additional compiler and linker options. Specified
 403    options are appended after the options set by the OpenCL program in
 404    ``clBuildProgram``.
 405 ``CLOVER_EXTRA_COMPILE_OPTIONS``
 406    allows specifying additional compiler options. Specified options are
 407    appended after the options set by the OpenCL program in
 408    ``clCompileProgram``.
 409 ``CLOVER_EXTRA_LINK_OPTIONS``
 410    allows specifying additional linker options. Specified options are
 411    appended after the options set by the OpenCL program in
 412    ``clLinkProgram``.
 413
 414 Softpipe driver environment variables
 415 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 416
 417 ``SOFTPIPE_DUMP_FS``
 418    if set, the softpipe driver will print fragment shaders to stderr
 419 ``SOFTPIPE_DUMP_GS``
 420    if set, the softpipe driver will print geometry shaders to stderr
 421 ``SOFTPIPE_NO_RAST``
 422    if set, rasterization is no-op'd. For profiling purposes.
 423 ``SOFTPIPE_USE_LLVM``
 424    if set, the softpipe driver will try to use LLVM JIT for vertex
 425    shading processing.
 426
 427 LLVMpipe driver environment variables
 428 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 429
 430 ``LP_NO_RAST``
 431    if set LLVMpipe will no-op rasterization
 432 ``LP_DEBUG``
 433    a comma-separated list of debug options is accepted. See the source
 434    code for details.
 435 ``LP_PERF``
 436    a comma-separated list of options to selectively no-op various parts
 437    of the driver. See the source code for details.
 438 ``LP_NUM_THREADS``
 439    an integer indicating how many threads to use for rendering. Zero
 440    turns off threading completely. The default value is the number of
 441    CPU cores present.
 442
 443 VMware SVGA driver environment variables
 444 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 445
 446 ``SVGA_FORCE_SWTNL``
 447    force use of software vertex transformation
 448 ``SVGA_NO_SWTNL``
 449    don't allow software vertex transformation fallbacks (will often
 450    result in incorrect rendering).
 451 ``SVGA_DEBUG``
 452    for dumping shaders, constant buffers, etc. See the code for details.
 453 ``SVGA_EXTRA_LOGGING``
 454    if set, enables extra logging to the ``vmware.log`` file, such as the
 455    OpenGL program's name and command line arguments.
 456 ``SVGA_NO_LOGGING``
 457    if set, disables logging to the ``vmware.log`` file. This is useful
 458    when using Valgrind because it otherwise crashes when initializing
 459    the host log feature.
 460
 461 See the driver code for other, lesser-used variables.
 462
 463 WGL environment variables
 464 ~~~~~~~~~~~~~~~~~~~~~~~~~
 465
 466 ``WGL_SWAP_INTERVAL``
 467    to set a swap interval, equivalent to calling
 468    ``wglSwapIntervalEXT()`` in an application. If this environment
 469    variable is set, application calls to ``wglSwapIntervalEXT()`` will
 470    have no effect.
 471
 472 VA-API environment variables
 473 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 474
 475 ``VAAPI_MPEG4_ENABLED``
 476    enable MPEG4 for VA-API, disabled by default.
 477
 478 VC4 driver environment variables
 479 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 480
 481 ``VC4_DEBUG``
 482    a comma-separated list of named flags, which do various things:
 483
 484    ``cl``
 485       dump command list during creation
 486    ``qpu``
 487       dump generated QPU instructions
 488    ``qir``
 489       dump QPU IR during program compile
 490    ``nir``
 491       dump NIR during program compile
 492    ``tgsi``
 493       dump TGSI during program compile
 494    ``shaderdb``
 495       dump program compile information for shader-db analysis
 496    ``perf``
 497       print during performance-related events
 498    ``norast``
 499       skip actual hardware execution of commands
 500    ``always_flush``
 501       flush after each draw call
 502    ``always_sync``
 503       wait for finish after each flush
 504    ``dump``
 505       write a GPU command stream trace file (VC4 simulator only)
 506
 507 RADV driver environment variables
 508 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 509
 510 ``RADV_DEBUG``
 511    a comma-separated list of named flags, which do various things:
 512
 513    ``llvm``
 514       enable LLVM compiler backend
 515    ``allbos``
 516       force all allocated buffers to be referenced in submissions
 517    ``allentrypoints``
 518       enable all device/instance entrypoints
 519    ``checkir``
 520       validate the LLVM IR before LLVM compiles the shader
 521    ``errors``
 522       display more info about errors
 523    ``info``
 524       show GPU-related information
 525    ``metashaders``
 526       dump internal meta shaders
 527    ``nobinning``
 528       disable primitive binning
 529    ``nocache``
 530       disable shaders cache
 531    ``nocompute``
 532       disable compute queue
 533    ``nodcc``
 534       disable Delta Color Compression (DCC) on images
 535    ``nodynamicbounds``
 536       do not check OOB access for dynamic descriptors
 537    ``nofastclears``
 538       disable fast color/depthstencil clears
 539    ``nohiz``
 540       disable HIZ for depthstencil images
 541    ``noibs``
 542       disable directly recording command buffers in GPU-visible memory
 543    ``nomemorycache``
 544       disable memory shaders cache
 545    ``nongg``
 546       disable NGG for GFX10+
 547    ``nooutoforder``
 548       disable out-of-order rasterization
 549    ``nothreadllvm``
 550       disable LLVM threaded compilation
 551    ``preoptir``
 552       dump LLVM IR before any optimizations
 553    ``shaders``
 554       dump shaders
 555    ``shaderstats``
 556       dump shader statistics
 557    ``spirv``
 558       dump SPIR-V
 559    ``startup``
 560       display info at startup
 561    ``syncshaders``
 562       synchronize shaders after all draws/dispatches
 563    ``vmfaults``
 564       check for VM memory faults via dmesg
 565    ``zerovram``
 566       initialize all memory allocated in VRAM as zero
 567
 568 ``RADV_FORCE_FAMILY``
 569    create a null device to compile shaders without a AMD GPU (eg.
 570    gfx900)
 571 ``RADV_PERFTEST``
 572    a comma-separated list of named flags, which do various things:
 573
 574    ``bolist``
 575       enable the global BO list
 576    ``cswave32``
 577       enable wave32 for compute shaders (GFX10+)
 578    ``dccmsaa``
 579       enable DCC for MSAA images
 580    ``dfsm``
 581       enable dfsm
 582    ``gewave32``
 583       enable wave32 for vertex/tess/geometry shaders (GFX10+)
 584    ``localbos``
 585       enable local BOs
 586    ``pswave32``
 587       enable wave32 for pixel shaders (GFX10+)
 588    ``tccompatcmask``
 589       enable TC-compat cmask for MSAA images
 590
 591 ``RADV_SECURE_COMPILE_THREADS``
 592    maximum number of secure compile threads (up to 32)
 593 ``RADV_TEX_ANISO``
 594    force anisotropy filter (up to 16)
 595 ``RADV_TRACE_FILE``
 596    generate cmdbuffer tracefiles when a GPU hang is detected
 597 ``ACO_DEBUG``
 598    a comma-separated list of named flags, which do various things:
 599
 600    ``validateir``
 601       validate the ACO IR at various points of compilation (enabled by
 602       default for debug/debugoptimized builds)
 603    ``validatera``
 604       validate register assignment of ACO IR and catches many RA bugs
 605    ``perfwarn``
 606       abort on some suboptimal code generation
 607
 608 radeonsi driver environment variables
 609 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 610
 611 ``AMD_DEBUG``
 612    a comma-separated list of named flags, which do various things:
 613 ``nodma``
 614    Disable SDMA
 615 ``nodmaclear``
 616    Disable SDMA clears
 617 ``nodmacopyimage``
 618    Disable SDMA image copies
 619 ``zerovram``
 620    Clear VRAM allocations.
 621 ``nodcc``
 622    Disable DCC.
 623 ``nodccclear``
 624    Disable DCC fast clear.
 625 ``nodccfb``
 626    Disable separate DCC on the main framebuffer
 627 ``nodccmsaa``
 628    Disable DCC for MSAA
 629 ``nodpbb``
 630    Disable DPBB.
 631 ``nodfsm``
 632    Disable DFSM.
 633 ``notiling``
 634    Disable tiling
 635 ``nofmask``
 636    Disable MSAA compression
 637 ``nohyperz``
 638    Disable Hyper-Z
 639 ``norbplus``
 640    Disable RB+.
 641 ``no2d``
 642    Disable 2D tiling
 643 ``info``
 644    Print driver information
 645 ``tex``
 646    Print texture info
 647 ``compute``
 648    Print compute info
 649 ``vm``
 650    Print virtual addresses when creating resources
 651 ``vs``
 652    Print vertex shaders
 653 ``ps``
 654    Print pixel shaders
 655 ``gs``
 656    Print geometry shaders
 657 ``tcs``
 658    Print tessellation control shaders
 659 ``tes``
 660    Print tessellation evaluation shaders
 661 ``cs``
 662    Print compute shaders
 663 ``noir``
 664    Don't print the LLVM IR
 665 ``nonir``
 666    Don't print NIR when printing shaders
 667 ``noasm``
 668    Don't print disassembled shaders
 669 ``preoptir``
 670    Print the LLVM IR before initial optimizations
 671 ``gisel``
 672    Enable LLVM global instruction selector.
 673 ``w32ge``
 674    Use Wave32 for vertex, tessellation, and geometry shaders.
 675 ``w32ps``
 676    Use Wave32 for pixel shaders.
 677 ``w32cs``
 678    Use Wave32 for computes shaders.
 679 ``w64ge``
 680    Use Wave64 for vertex, tessellation, and geometry shaders.
 681 ``w64ps``
 682    Use Wave64 for pixel shaders.
 683 ``w64cs``
 684    Use Wave64 for computes shaders.
 685 ``checkir``
 686    Enable additional sanity checks on shader IR
 687 ``mono``
 688    Use old-style monolithic shaders compiled on demand
 689 ``nooptvariant``
 690    Disable compiling optimized shader variants.
 691 ``forcedma``
 692    Use SDMA for all operations when possible.
 693 ``nowc``
 694    Disable GTT write combining
 695 ``check_vm``
 696    Check VM faults and dump debug info.
 697 ``reserve_vmid``
 698    Force VMID reservation per context.
 699 ``nogfx``
 700    Disable graphics. Only multimedia compute paths can be used.
 701 ``nongg``
 702    Disable NGG and use the legacy pipeline.
 703 ``nggc``
 704    Always use NGG culling even when it can hurt.
 705 ``nonggc``
 706    Disable NGG culling.
 707 ``alwayspd``
 708    Always enable the primitive discard compute shader.
 709 ``pd``
 710    Enable the primitive discard compute shader for large draw calls.
 711 ``nopd``
 712    Disable the primitive discard compute shader.
 713 ``switch_on_eop``
 714    Program WD/IA to switch on end-of-packet.
 715 ``nooutoforder``
 716    Disable out-of-order rasterization
 717 ``dpbb``
 718    Enable DPBB.
 719 ``dfsm``
 720    Enable DFSM.
 721
 722 Other Gallium drivers have their own environment variables. These may
 723 change frequently so the source code should be consulted for details.