intel(4) Kernel Interfaces Manual intel(4)
intel - Intel integrated graphics chipsets
intel is an Xorg driver for Intel integrated graphics chipsets. The
driver supports depths 8, 15, 16 and 24. All visual types are sup-
ported in depth 8. For the i810/i815 other depths support the True-
Color and DirectColor visuals. For the i830M and later, only the True-
Color visual is supported for depths greater than 8. The driver sup-
ports hardware accelerated 3D via the Direct Rendering Infrastructure
(DRI), but only in depth 16 for the i810/i815 and depths 16 and 24 for
the 830M and later.
intel supports the i810, i810-DC100, i810e, i815, i830M, 845G, 852GM,
855GM, 865G, 915G, 915GM, 945G, 945GM, 965G, 965Q, 946GZ, 965GM,
945GME, G33, Q33, and Q35 chipsets.
Please refer to xorg.conf(5) for general configuration details. This
section only covers configuration details specific to this driver.
The Intel 8xx and 9xx families of integrated graphics chipsets have a
unified memory architecture and uses system memory for video ram. For
the i810 and i815 family of chipset, operating system support for allo-
cating system memory for video use is required in order to use this
driver. For the 830M and later, this is required in order for the
driver to use more video ram than has been pre-allocated at boot time
by the BIOS. This is usually achieved with an "agpgart" or "agp" ker-
nel driver. Linux, FreeBSD, OpenBSD, NetBSD, and Solaris have such
kernel drivers available.
By default, the i810 will use 8 megabytes of system memory for graph-
ics. For the 830M and later, the driver will automatically size its
memory allocation according to the features it will support. The Vide-
oRam option, which in the past had been necessary to allow more than
some small amount of memory to be allocated, is now ignored.
The following driver Options are supported
Option "NoAccel" "boolean"
Disable or enable acceleration. Default: acceleration is
Option "SWCursor" "boolean"
Disable or enable software cursor. Default: software cursor is
disable and a hardware cursor is used for configurations where
the hardware cursor is available.
Option "ColorKey" "integer"
This sets the default pixel value for the YUV video overlay key.
Option "CacheLines" "integer"
This allows the user to change the amount of graphics memory
used for 2D acceleration and video when XAA acceleration is
enabled. Decreasing this amount leaves more for 3D textures.
Increasing it can improve 2D performance at the expense of 3D
performance. Default: depends on the resolution, depth, and
available video memory. The driver attempts to allocate space
for at 3 screenfuls of pixmaps plus an HD-sized XV video. The
default used for a specific configuration can be found by exam-
ining the Xorg log file.
Option "FramebufferCompression" "boolean"
This option controls whether the framebuffer compression feature
is enabled. If possible, the front buffer will be allocated in
a tiled format and compressed periodically to save memory band-
width and power. This option is only available on mobile
chipsets. Default: enabled on supported configurations.
Option "Tiling" "boolean"
This option controls whether memory buffers are allocated in
tiled mode. In many cases (especially for complex rendering),
tiling can improve performance. Default: enabled.
Option "DRI" "boolean"
Disable or enable DRI support. Default: DRI is enabled for con-
figurations where it is supported.
Option "RenderAccel" "boolean"
This option controls whether EXA composite acceleration is
enabled. Default: disabled on i965 and higher.
The following driver Options are supported for the i810 and i815
Option "DDC" "boolean"
Disable or enable DDC support. Default: enabled.
Option "Dac6Bit" "boolean"
Enable or disable 6-bits per RGB for 8-bit modes. Default:
8-bits per RGB for 8-bit modes.
Option "XvMCSurfaces" "integer"
This option enables XvMC. The integer parameter specifies the
number of surfaces to use. Valid values are 6 and 7. Default:
XvMC is disabled.
The following driver Options are supported for the 830M and later
Option "VideoKey" "integer"
This is the same as the "ColorKey" option described above. It
is provided for compatibility with most other drivers.
Option "XVideo" "boolean"
Disable or enable XVideo support. Default: XVideo is enabled
for configurations where it is supported.
Option "Legacy3D" "boolean"
Enable support for the legacy i915_dri.so 3D driver. This will,
among other things, make the 2D driver tell libGL to load the 3D
driver i915_dri.so instead of the newer i915tex_dri.so. This
option is only used for chipsets in the range i830-i945.
Default for i830-i945 series: Enabled. Default for i810: The
option is not used. Default for i965: The option is always
Option "AperTexSize" "integer"
Give the size in kiB of the AGP aperture area that is reserved
for the DRM memory manager present in i915 drm from version
1.7.0 and upwards, and that is used with the 3D driver in Mesa
from version 6.5.2 and upwards. If the size is set too high to
make room for pre-allocated VideoRam, the driver will try to
reduce it automatically. If you use only older Mesa or DRM ver-
sions, you may set this value to zero, and activate the legacy
texture pool (see Option "Legacy3D" ). If you run 3D programs
with large texture memory requirements, you might gain some per-
formance by increasing this value. Default: 32768.
Option "PageFlip" "boolean"
Enable support for page flipping. This should improve 3D perfor-
mance at the potential cost of worse performance with mixed
2D/3D. Also note that this gives no benefit without correspond-
ing support in the Mesa 3D driver and may not give the full ben-
efit without triple buffering (see Option "TripleBuffer" ).
Default for i810: The option is not used. Default for i830 and
above: Disabled (This option is currently unstable).
Option "TripleBuffer" "boolean"
Enable support for triple buffering. This should improve 3D per-
formance at the potential cost of worse performance with mixed
2D/3D. Also note that this gives no benefit without correspond-
ing support in the Mesa 3D driver and may not give any benefit
without page flipping either (see Option "PageFlip" ). Default
for i810: The option is not used. Default for i830 and above:
Option "AccelMethod" "string"
Choose acceleration architecture, either "XAA" or "EXA". XAA is
the old XFree86 based acceleration architecture. EXA is a newer
and simpler acceleration architecture designed to better accel-
erate the X Render extension. Default: "EXA".
Option "ModeDebug" "boolean"
Enable printing of additional debugging information about mode-
setting to the server log.
Option "ForceEnablePipeA" "boolean"
Force the driver to leave pipe A enabled. May be necessary in
configurations where the BIOS accesses pipe registers during
display hotswitch or lid close, causing a crash. If you find
that your platform needs this option, please file a bug against
xf86-video-intel at http://bugs.freedesktop.org which includes
the output of 'lspci -v' and 'lspci -vn'.
Option "LVDS24Bit" "boolean"
Specify 24 bit pixel format (i.e. 8 bits per color) to be used
for the LVDS output. Some newer LCD panels expect pixels to be
formatted and sent as 8 bits per color channel instead of the
more common 6 bits per color channel. Set this option to true
to enable the newer format. Note that this concept is entirely
different and independent from the frame buffer color depth -
which is still controlled in the usual way within the X server.
This option instead selects the physical format / sequencing of
the digital bits sent to the display. Setting the frame buffer
color depth is really a matter of preference by the user, while
setting the pixel format here is a requirement of the connected
hardware. Leaving this unset implies the default value of
false, which is almost always going to be right choice. If your
LVDS-connected display on the other hand is extremely washed out
(e.g. white on a lighter white), trying this option might clear
Option "LVDSFixedMode" "boolean"
Use a fixed set of timings for the LVDS output, independent of
normal xorg specified timings. The default value if left
unspecified is true, which is what you want for a normal LVDS-
connected LCD type of panel. If you are not sure about this,
leave it at its default, which allows the driver to automati-
cally figure out the correct fixed panel timings. See further
in the section about LVDS fixed timing for more information.
Option "XvMC" "boolean"
Enable XvMC driver. Current support MPEG2 MC on 915/945 and G33
series. User should provide absolute path to libIntelXvMC.so in
XvMCConfig file. Default: Disabled.
On 830M and better chipsets, the driver supports runtime configuration
of detected outputs. You can use the xrandr tool to control outputs on
the command line. Each output listed below may have one or more prop-
erties associated with it (like a binary EDID block if one is found).
Some outputs have unique properties which are described below.
VGA output port (typically exposed via an HD15 connector).
Low Voltage Differential Signalling output (typically a laptop LCD
panel). Available properties:
BACKLIGHT - current backlight level (adjustable)
By adjusting the BACKLIGHT property, the brightness on the LVDS output
can be adjusted. In some cases, this property may be unavailable (for
example if your platform uses an external microcontroller to control
BACKLIGHT_CONTROL - method used to control backlight
The driver will attempt to automatically detect the backlight control
method for your platform. If this fails however, you can select
another method which may allow you to control your backlight. Avail-
able methods include:
Intel chipsets include backlight control registers, which on some plat-
forms may be wired to control the backlight directly. This method uses
The legacy backlight control registers exist in PCI configuration
space, and have fewer available backlight levels than the native regis-
ters. However, some platforms are wired this way and so need to use
This method attempts to use the native registers where possible,
resorting to the legacy, configuration space registers only to enable
the backlight if needed. On platforms that have both wired this can be
a good choice as it allows the fine grained backlight control of the
On some system, the kernel may provide a backlight control driver. In
that case, using the kernel interfaces is preferable, as the same
driver may respond to hotkey events or external APIs.
PANEL_FITTING - control LCD panel fitting
By default, the driver will attempt to upscale resolutions smaller than
the LCD's native size while preserving the aspect ratio. Other modes
are available however:
Simply center the image on-screen, without scaling.
The default mode. Try to upscale the image to the screen size, while
preserving aspect ratio. May result in letterboxing or pillar-boxing
with some resolutions.
Upscale the image to the native screen size without regard to aspect
ratio. In this mode, the full screen image may appear distorted in
Integrated TV output. Available properties include:
BOTTOM, RIGHT, TOP, LEFT - margins
Adjusting these properties allows you to control the placement of your
TV output buffer on the screen.
TV_FORMAT - output standard
This property allows you to control the output standard used on your TV
output port. You can select between NTSC-M, NTSC-443, NTSC-J, PAL-M,
PAL-N, and PAL.
First DVI SDVO output
Second DVI SDVO output
SDVO and DVO TV outputs are not supported by the driver at this time.
See xorg.conf(5) for information on associating Monitor sections with
these outputs for configuration. Associating Monitor sections with
each output can be helpful if you need to ignore a specific output, for
example, or statically configure an extended desktop monitor layout.
HARDWARE LVDS FIXED TIMINGS AND SCALING
Following here is a discussion that should shed some light on the
nature and reasoning behind the LVDSFixedMode option.
Unlike a CRT display, an LCD has a "native" resolution corresponding to
the actual pixel geometry. A graphics controller under all normal cir-
cumstances should always output that resolution (and timings) to the
display. Anything else and the image might not fill the display, it
might not be centered, or it might have information missing - any man-
ner of strange effects can happen if an LCD panel is not fed with the
expected resolution and timings.
However there are cases where one might want to run an LCD panel at an
effective resolution other than the native one. And for this reason,
GPUs which drive LCD panels typically include a hardware scaler to
match the user-configured frame buffer size to the actual size of the
panel. Thus when one "sets" his/her 1280x1024 panel to only 1024x768,
the GPU happily configures a 1024x768 frame buffer, but it scans the
buffer out in such a way that the image is scaled to 1280x1024 and in
fact sends 1280x1024 to the panel. This is normally invisible to the
user; when a "fuzzy" LCD image is seen, scaling like this is why this
In order to make this magic work, this driver logically has to be con-
figured with two sets of monitor timings - the set specified (or other-
wise determined) as the normal xorg "mode", and the "fixed" timings
that are actually sent to the monitor. But with xorg, it's only possi-
ble to specify the first user-driven set, and not the second fixed set.
So how does the driver figure out the correct fixed panel timings?
Normally it will attempt to detect the fixed timings, and it uses a
number of strategies to figure this out. First it attempts to read
EDID data from whatever is connected to the LVDS port. Failing that,
it will check if the LVDS output is already configured (perhaps previ-
ously by the video BIOS) and will adopt those settings if found. Fail-
ing that, it will scan the video BIOS ROM, looking for an embedded mode
table from which it can infer the proper timings. If even that fails,
then the driver gives up, prints the message "Couldn't detect panel
mode. Disabling panel" to the X server log, and shuts down the LVDS
Under most circumstances, the detection scheme works. However there
are cases when it can go awry. For example, if you have a panel with-
out EDID support and it isn't integral to the motherboard (i.e. not a
laptop), then odds are the driver is either not going to find something
suitable to use or it is going to find something flat-out wrong, leav-
ing a messed up display. Remember that this is about the fixed timings
being discussed here and not the user-specified timings which can
always be set in xorg.conf in the worst case. So when this process
goes awry there seems to be little recourse. This sort of scenario can
happen in some embedded applications.
The LVDSFixedMode option is present to deal with this. This option
normally enables the above-described detection strategy. And since it
defaults to true, this is in fact what normally happens. However if
the detection fails to do the right thing, the LVDSFixedMode option can
instead be set to false, which disables all the magic. With LVDSFixed-
Mode set to false, the detection steps are skipped and the driver pro-
ceeds without a specified fixed mode timing. This then causes the
hardware scaler to be disabled, and the actual timings then used fall
back to those normally configured via the usual xorg mechanisms.
Having LVDSFixedMode set to false means that whatever is used for the
monitor's mode (e.g. a modeline setting) is precisely what is sent to
the device connected to the LVDS port. This also means that the user
now has to determine the correct mode to use - but it's really no dif-
ferent than the work for correctly configuring an old-school CRT any-
way, and the alternative if detection fails will be a useless display.
In short, leave LVDSFixedMode alone (thus set to true) and normal fixed
mode detection will take place, which in most cases is exactly what is
needed. Set LVDSFixedMode to false and then the user has full control
over the resolution and timings sent to the LVDS-connected device,
through the usual means in xorg.
Xorg(1), xorg.conf(5), xorgconfig(1), Xserver(1), X(7)
Authors include: Keith Whitwell, and also Jonathan Bian, Matthew J Sot-
tek, Jeff Hartmann, Mark Vojkovich, Alan Hourihane, H. J. Lu. 830M and
845G support reworked for XFree86 4.3 by David Dawes and Keith
Whitwell. 852GM, 855GM, and 865G support added by David Dawes and
Keith Whitwell. 915G, 915GM, 945G, 945GM, 965G, 965Q and 946GZ support
added by Alan Hourihane and Keith Whitwell. Lid status support added by
Alan Hourihane. Textured video support for 915G and later chips, RandR
1.2 and hardware modesetting added by Eric Anholt and Keith Packard.
EXA and Render acceleration added by Wang Zhenyu. TV out support added
by Zou Nan Hai and Keith Packard. 965GM, G33, Q33, and Q35 support
added by Wang Zhenyu.
X Version 11 xf86-video-intel 2.3.2 intel(4)