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 configurations. Acceleration is avail-
able through glamor for devices supporting at least OpenGL ES 2.0 or
OpenGL 2.1. If glamor is not enabled, a shadow framebuffer is config-
ured 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 sec-
tion of the config file. The modesetting driver can pick up the cur-
rently 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 sec-
tion. 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 frame-
buffer 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 function (typically VNC), where remote up-
dates are triggered by any framebuffer write, so minimizing the
amount of data uploaded is crucial. This defaults to enabled
for ASPEED 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 displays 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 syn-
chronize their flips. This may cause some tearing on these dis-
plays, but it prevents a permanent or periodic slowdown or irri-
tating 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 par-
ticular 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 21.1.4 MODESETTING(4)
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