man > modesetting(4)

MODESETTING(4)                        Kernel Interfaces Manual                        MODESETTING(4)

NAME
       modesetting - video driver for framebuffer device

SYNOPSIS
       Section "Device"
         Identifier "devname"
         Driver "modesetting"
         BusID  "pci:bus:dev:func"
         ...
       EndSection

DESCRIPTION
       modesetting  is  an  Xorg  driver for KMS devices.  This driver supports TrueColor visuals at
       framebuffer depths of 15, 16, 24, and 30. RandR 1.2 is supported  for  multi-head  configura‐
       tions. Acceleration is available through glamor for devices supporting at least OpenGL ES 2.0
       or OpenGL 2.1.  If glamor is not enabled, a shadow framebuffer is configured based on the KMS
       drivers'  preference  (unless  the framebuffer is 24 bits per pixel, in which case the shadow
       framebuffer is always used).

SUPPORTED HARDWARE
       The modesetting driver supports all hardware where a KMS driver  is  available.   modesetting
       uses the Linux DRM KMS ioctls and dumb object create/map.

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

       For this driver it is not required to specify modes in the screen section of the config file.
       The modesetting driver can pick up the currently used video mode from the kernel  driver  and
       will use it if there are no video modes configured.

       For  PCI  boards  you  might have to add a BusID line to the Device section.  See above for a
       sample line.

       The following driver Options are supported:

       Option "SWcursor" "boolean"
              Selects software cursor.  The default is off.

       Option "kmsdev" "string"
              The framebuffer device to use. Default: /dev/dri/card0.

       Option "ShadowFB" "boolean"
              Enable or disable use of the shadow framebuffer layer.  Default: on.

       Option "DoubleShadow" "boolean"
              Double-buffer shadow updates. When enabled, the driver will keep  two  copies  of  the
              shadow  framebuffer.  When the shadow framebuffer is flushed, the old and new versions
              of the shadow are compared, and only tiles that have actually changed are uploaded  to
              the  device. This is an optimization for server-class GPUs with a remote display func‐
              tion (typically VNC), where remote updates are triggered by any framebuffer write,  so
              minimizing  the  amount of data uploaded is crucial.  This defaults to enabled for AS‐
              PEED and Matrox G200 devices, and disabled otherwise.

       Option "AccelMethod" "string"
              One of "glamor" or "none".  Default: glamor.

       Option "PageFlip" "boolean"
              Enable DRI3 page flipping.  The default is on.

       Option "VariableRefresh" "boolean"
              Enables support for enabling variable refresh on the Screen's CRTCs when  an  suitable
              application is flipping via the Present extension.
              The default is off.

       Option "AsyncFlipSecondaries" "boolean"
              Use  async  flips for secondary video outputs on multi-display setups. If a screen has
              multiple displays attached and DRI3 page flipping is used, then only one of  the  dis‐
              plays  will have its page flip synchronized to vblank for tear-free presentation. This
              is the display that is used for presentation timing and timestamping, usually the  one
              covering  the  biggest  pixel  area of the screen.  All other displays ("Secondaries")
              will not synchronize their flips. This may cause some tearing on these  displays,  but
              it prevents a permanent or periodic slowdown or irritating judder of animations if not
              all  video  outputs are running synchronized with each other and with the same refresh
              rate. There is no perfect solution apart from perfectly synchronized outputs, but this
              option may give preferrable results if the displays in a multi-display setup mirror or
              clone each other.  The default is off.

       Option "ZaphodHeads" "string"
              Specify the RandR output(s) to use with zaphod mode for a particular driver  instance.
              If you use this option you must use this option for all instances of the driver.
              For  example:  Option  "ZaphodHeads"  "LVDS,VGA-0" will assign xrandr outputs LVDS and
              VGA-0 to this instance of the driver.

       Option "UseGammaLUT" "boolean"
              Enable or disable use of the GAMMA_LUT property, when available.  When  enabled,  this
              option  allows  the  driver  to use gamma ramps with more entries, if supported by the
              kernel. By default, GAMMA_LUT will be used for kms drivers which are known to be  safe
              for use of GAMMA_LUT.

       SEE ALSO
              Xorg(1), xorg.conf(5), Xserver(1), X(7)

AUTHORS
       Authors include: Dave Airlie

X Version 11                             xorg-server 21.1.11                          MODESETTING(4)