Provided by: xserver-xorg-video-openchrome_0.3.3+git20160310-1_i386 bug


       openchrome - video driver for VIA Unichromes


       Section "Device"
         Identifier "devname"
         Driver "openchrome"


       openchrome  is  an Xorg driver for VIA chipsets that have an integrated
       Unichrome graphics engine.

       The  openchrome  driver  supports  the  following   chipsets:   CLE266,
       KM400/KN400/KM400A/P4M800,       CN400/PM800/PN800/PM880,       K8M800,
       CN700/VM800/P4M800Pro,  CX700,  P4M890,   K8M890,   P4M900/VN896/CN896,
       VX800,  VX855  and  VX900.   The driver includes 2D acceleration and Xv
       video  overlay  extensions.   Flat  panel,  TV,  and  VGA  outputs  are
       supported, depending on the hardware configuration.

       3D  direct  rendering is available using experimental drivers from Mesa
       (  There is also an XvMC client  library  for  hardware
       acceleration  of  MPEG1/MPEG2  decoding  (not available on the KM/N400)
       that uses the Direct Rendering Infrastructure (DRI).  The  XvMC  client
       library implements a non-standard "VLD" extension to the XvMC standard.
       The current Direct Rendering Manager (DRM) kernel module  is  available

       The  driver  supports  free  modes  for  Unichrome Pros (K8M800/K8N800,
       PM800/PN800, and CN400).  For plain Unichromes  (CLE266,  KM400/KN400),
       it currently supports only a limited number of dotclocks, so if you are
       using X modelines you must make sure that the dotclock is one of  those
       supported.   Supported  dotclocks on plain Unichromes are currently (in
       MHz): 25.2, 25.312, 26.591, 31.5, 31.704, 32.663, 33.750,  35.5,  36.0,
       39.822,  40.0,  41.164, 46.981, 49.5, 50.0, 56.3, 57.284, 64.995, 65.0,
       65.028,  74.480,  75.0,  78.8,  81.613,  94.5,  108.0,  108.28,  122.0,
       122.726,  135.0,  148.5,  155.8,  157.5,  161.793, 162.0, 175.5, 189.0,
       202.5, 204.8, 218.3, 229.5.  On top  of  this,  bandwidth  restrictions
       apply for both Unichromes and Unichrome Pros.


       Please  refer  to xorg.conf(5) for general configuration details.  This
       section only covers configuration details specific to this driver.

       The following driver options are supported:

       Option "AccelMethod"  "string"
              The driver supports "XAA" and "EXA" acceleration  methods.   The
              default   method  is  XAA,  since  EXA  is  still  experimental.
              Contrary to XAA, EXA implements acceleration for screen  uploads
              and  downloads  (if DRI is enabled) and for the Render/Composite

       Option "ActiveDevice"  "string"
              Specifies the active device combination.  Any string  containing
              "CRT",  "LCD",  "DFP", "TV" should be possible. "CRT" represents
              anything that is connected to the VGA port, "LCD" is for  laptop
              panels  (not TFT screens attached to the VGA port), "DFP" is for
              screens connected to the DVI  port,  "TV"  is  self-explanatory.
              The default is to use what is detected.  The driver is currently
              unable to use LCD and TV simultaneously,  and  will  favour  the
              LCD.   The  DVI  port  is  not  properly  probed and needs to be
              enabled with this option.

       Option "AGPMem"  "integer"
              Sets the amount of AGP memory that  is  allocated  at  X  server
              startup.   The  allocated memory will be "integer" kB.  This AGP
              memory is used  for  the  AGP  command  buffer  (if  the  option
              "EnableAGPDMA"  is set to "true"), for DRI textures, and for the
              EXA scratch area.  The driver will allocate at least one  system
              page  of  AGP memory, or -- if the AGP command buffer is used --
              at least 2 MB plus one system page.  If there is no room for the
              EXA  scratch  area in AGP space, it will be allocated from VRAM.
              If there is no room for DRI textures,  they  will  be  allocated
              from  the  DRI  part  of VRAM (see the option "MaxDRIMem").  The
              default amount of AGP is 32768 kB.  Note that the  AGP  aperture
              set  in  the  BIOS must be able to accommodate the amount of AGP
              memory  specified  here.   Otherwise  no  AGP  memory  will   be
              available.   It  is safe to set a very large AGP aperture in the

       Option "Center"  "boolean"
              Enables  image  centering  on  DVI  displays.   The  default  is

       Option "DisableIRQ"  "boolean"
              Disables  the vertical blank IRQ.  This is a workaround for some
              mainboards  that  have  problems  with  IRQs  coming  from   the
              Unichrome  engine.   With IRQs disabled, DRI clients have no way
              to synchronize their drawing to Vblank.   (IRQ  is  disabled  by
              default on the KM400 and K8M800 chipsets.)

       Option "DisableVQ"  "boolean"
              Disables  the  use  of  the virtual command queue.  The queue is
              enabled by default.

       Option "EnableAGPDMA"  "boolean"
              Enables the AGP DMA functionality in DRM.   This  requires  that
              DRI  is enabled and will force 2D and 3D acceleration to use AGP
              DMA.  The XvMC DRI client will also make  use  of  this  on  the
              CLE266  to  consume  much  less CPU.  (This option is enabled by
              default, except on the K8M890 and P4M900.)

       Option "ExaNoComposite"  "boolean"
              If EXA is enabled (using the option "AccelMethod"), this  option
              enables   acceleration   of  compositing.   Since  EXA,  and  in
              particular its composite acceleration,  is  still  experimental,
              this is a way to disable a misbehaving composite acceleration.

       Option "ExaScratchSize"  "integer"
              Sets  the  size  of  the EXA scratch area to "integer" kB.  This
              area is used by EXA as a last place to look for available  space
              for pixmaps.  Too little space will slow compositing down.  This
              option should be set to the size of the largest pixmap used.  If
              you  have a screen width of over 1024 pixels and use 24 bpp, set
              this to 8192.  Otherwise you can leave this at the default 4096.
              The  space  will  be  allocated  from  AGP  memory if available,
              otherwise from VRAM.

       Option "LCDDualEdge"  "boolean"
              Enables the use of dual-edge mode to set the LCD.   The  default
              is disabled.

       Option "MaxDRIMem"  "integer"
              Sets the maximum amount of VRAM memory allocated for DRI clients
              to "integer" kB.  Normally DRI clients  get half  the  available
              VRAM  size,  but  in  some cases it may make sense to limit this
              amount.  For example, if you are using a composite  manager  and
              you  want  to  give as much memory as possible to the EXA pixmap
              storage area.

       Option "MigrationHeuristic"  "string"
              Sets the heuristic for EXA pixmap migration.   This  is  an  EXA
              core  option,  and  starting from Xorg server version 1.3.0 this
              defaults to "always".  The openchrome driver performs best  with
              "greedy",   so  you  should  really  add  this  option  to  your
              configuration file.  The third possibility is "smart".

       Option "NoAccel"  "boolean"
              Disables the use  of  hardware  acceleration.   Acceleration  is
              enabled by default.

       Option "NoAGPFor2D"  "boolean"
              Disables  the  use of AGP DMA for 2D acceleration, even when AGP
              DMA is enabled.  The default is enabled.

       Option "NoXVDMA"  "boolean"
              If DRI is enabled, Xv normally uses PCI DMA  to  transfer  video
              images  from  system  to  frame-buffer memory.  This is somewhat
              slower than direct copies due to the limitations of the PCI bus,
              but  on  the  other  hand  it decreases CPU usage significantly,
              particularly on computers  with  fast  processors.   Some  video
              players  are buggy and will display rendering artifacts when PCI
              DMA is used.  If you experience this, or don't want your PCI bus
              to  be stressed with Xv images, set this option to "true".  This
              option has no effect when DRI is not enabled.

       Option "PanelSize"  "string"
              Specifies the size (width x height) of the LCD panel attached to
              the  system.   The  sizes 640x480, 800x600, 1024x768, 1280x1024,
              and 1400x1050 are supported.

       Option "RotationType"  "string"
              Enabled  rotation  by  using  RandR.  The  driver  only  support
              unaccelerated  RandR  rotations  "SWRandR".  Hardware  rotations
              "HWRandR" is currently unimplemented.

       Option "Rotate"  "string"
              Rotates the display either  clockwise  ("CW"),  counterclockwise
              ("CCW")  and  upside-down  ("UD").  Rotation  is  only supported
              unaccelerated.  Adding option "Rotate", enables  RandR  rotation
              feature.   The  RandR  allows  clients  to  dynamically change X

       Option "ShadowFB"  "boolean"
              Enables the use of a shadow frame buffer.  This is required when
              rotating the display, but otherwise defaults to disabled.

       Option "SWCursor"  "boolean"
              Enables  the use of a software cursor.  The default is disabled:
              the hardware cursor is used.

       Option "TVDeflicker"  "integer"
              Specifies the deflicker setting for TV output.  Valid values are
              "0",  "1",  and  "2".   Here 0 means no deflicker, 1 means 1:1:1
              deflicker, and 2 means 1:2:1 deflicker.

       Option "TVDotCrawl"  "boolean"
              Enables dot-crawl suppression.  The default is disabled.

       Option "TVOutput"  "string"
              Specifies which TV output  to  use.   The  driver  supports  "S-
              Video",  "Composite",  "SC",  "RGB",  and "YCbCr" outputs.  Note
              that on some EPIA boards the composite-video port is shared with
              audio-out and is selected via a jumper.

       Option "TVPort"  "string"
              Specifies  TV  port.   The  driver  currently  supports  "DVP0",
              "DVP1", "DFPHigh" and "DFPLow" ports.

       Option "TVType"  "string"
              Specifies TV  output  format.   The  driver  currently  supports
              "NTSC" and "PAL" timings only.

       Option "VBEModes"  "boolean"
              Enables  the use of VBE BIOS calls for setting the display mode.
              This mimics the behaviour of the vesa driver but still  provides
              acceleration  and  other  features.   This option may be used if
              your hardware works with  the  vesa  driver  but  not  with  the
              openchrome  driver.   It  may not work on 64-bit systems.  Using
              "VBEModes" may speed up driver acceleration significantly due to
              a more aggressive hardware setting, particularly on systems with
              low memory bandwidth.  Your refresh rate may be limited to 60 Hz
              on some systems.

       Option "VBESaveRestore"  "boolean"
              Enables  the  use of VBE BIOS calls for saving and restoring the
              display state when the  X  server  is  launched.   This  can  be
              extremely  slow  on  some hardware, and the system may appear to
              have locked for 10 seconds or so.  The default  is  to  use  the
              driver  builtin  function.   This  option  only  works if option
              "VBEModes" is enabled.

       Option "VideoRAM"  "integer"
              Overrides the VideoRAM  autodetection.   This  should  never  be


       Unichromes tend to be paired with several different TV encoders.

       VIA Technologies VT1621
              Still  untested,  as no combination with a Unichrome is known or
              available.  Supports the following normal modes:  "640x480"  and
              "800x600".   Use  "640x480Over"  and  "800x600Over" for vertical
              overscan.   These  modes  are  made  available  by  the  driver;
              modelines provided in xorg.conf will be ignored.

       VIA Technologies VT1622, VT1622A, VT1623
              Supports  the following modes: "640x480", "800x600", "1024x768",
              "848x480", "720x480" (NTSC only) and "720x576" (PAL only).   Use
              "640x480Over",   "800x600Over",  "1024x768Over",  "848x480Over",
              "720x480Over"  (NTSC)  and  "720x576Over"  (PAL)  for   vertical
              overscan.      The    modes    "720x480Noscale"    (NTSC)    and
              "720x576Noscale"  (PAL)  (available  on  VT1622  only)   provide
              cleaner  TV output (unscaled with only minimal overscan).  These
              modes are made available by the driver;  modelines  provided  in
              xorg.conf will be ignored.


       Xorg(1), xorg.conf(5), Xserver(1), X(7), EXA(5), Xv(5)


       Authors include: ...