Provided by:
xserver-xorg-video-intel_2.6.3-0ubuntu9_i386 
NAME
intel - Intel integrated graphics chipsets
SYNOPSIS
Section "Device"
Identifier "devname"
Driver "intel"
...
EndSection
DESCRIPTION
intel is an Xorg driver for Intel integrated graphics chipsets. The
driver supports depths 8, 15, 16 and 24. All visual types are
supported in depth 8. For the i810/i815 other depths support the
TrueColor and DirectColor visuals. For the i830M and later, only the
TrueColor visual is supported for depths greater than 8. The driver
supports 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.
SUPPORTED HARDWARE
intel supports the i810, i810-DC100, i810e, i815, i830M, 845G, 852GM,
855GM, 865G, 915G, 915GM, 945G, 945GM, 965G, 965Q, 946GZ, 965GM,
945GME, G33, Q33, Q35, G35, GM45, G45, Q45, G43 and G41 chipsets.
CONFIGURATION DETAILS
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 meaning that system memory is used as video
RAM. For the i810 and i815 family of chipsets, operating system
support for allocating system memory 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"
kernel driver. Linux, FreeBSD, OpenBSD, NetBSD, and Solaris have such
kernel drivers available.
By default, the i810/i815 will use 8 MB of system memory for graphics
if AGP allocable memory is < 128 MB, 16 MB if < 192 MB or 24 MB if
higher. Use the VideoRam option to change the default value.
For the 830M and later, the driver will automatically size its memory
allocation according to the features it will support. Therefore, the
VideoRam 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
enabled.
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.
Default: undefined.
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
examining 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
bandwidth 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 most cases (especially for complex rendering),
tiling dramatically improves performance. Default: enabled.
Option "DRI" "boolean"
Disable or enable DRI support. Default: DRI is enabled for
configurations where it is supported.
The following driver Options are supported for the i810 and i815
chipsets:
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.
VideoRam integer
This option specifies the amount of system memory to use for
graphics, in KB. The default is 8192 if AGP allocable memory is
< 128 MB, 16384 if < 192 MB, 24576 if higher. DRI require at
least a value of 16384. Higher values may give better 3D
performance, at expense of available system memory.
The following driver Options are supported for the 830M and later
chipsets:
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 "XvPreferOverlay" "boolean"
Make hardware overlay be the first XV adaptor. The overlay
behaves incorrectly in the presence of compositing, but some
prefer it due to it syncing to vblank in the absence of
compositing. While most XV-using applications have options to
select which XV adaptor to use, this option can be used to place
the overlay first for applications which don’t have options for
selecting adaptors. Default: Textured video adaptor is
preferred.
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
accelerate the X Render extension. Default: "EXA".
Option "ModeDebug" "boolean"
Enable printing of additional debugging information about
modesetting to the server log. Default: Disabled
Option "FallbackDebug" "boolean"
Enable printing of debugging information on acceleration
fallbacks to the server log. Default: Disabled
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 (see
REPORTING BUGS below) including 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
the problem.
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
automatically 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.
Option "ForceSDVODetect" "boolean"
Instead of depending on SDVO detect status bit to initialize
SDVO outputs, this option trys to ignore that status bit and try
to probe on all SDVO ports anyway. Try this if some output is
not detected on your ADD2 card. Use of this option will slow
down your startup time. Default: Disabled.
OUTPUT CONFIGURATION
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
properties associated with it (like a binary EDID block if one is
found). Some outputs have unique properties which are described below.
See the "MULTIHEAD CONFIGURATIONS" section below for additional
information.
VGA
VGA output port (typically exposed via an HD15 connector).
LVDS
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
the backlight).
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.
Available methods include:
native
Intel chipsets include backlight control registers, which on some
platforms may be wired to control the backlight directly. This method
uses those registers.
legacy
The legacy backlight control registers exist in PCI configuration
space, and have fewer available backlight levels than the native
registers. However, some platforms are wired this way and so need to
use this method.
combo
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
native interface.
kernel
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:
center
Simply center the image on-screen, without scaling.
full_aspect
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.
full
Upscale the image to the native screen size without regard to aspect
ratio. In this mode, the full screen image may appear distorted in
some resolutions.
TV
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. The options with the same name can also
be set in xorg.conf with integer value.
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.
TMDS-1
First DVI SDVO output
TMDS-2
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
circumstances 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
manner 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
happens.
In order to make this magic work, this driver logically has to be
configured with two sets of monitor timings - the set specified (or
otherwise determined) as the normal xorg "mode", and the "fixed"
timings that are actually sent to the monitor. But with xorg, it’s
only possible 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
previously by the video BIOS) and will adopt those settings if found.
Failing 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 output.
Under most circumstances, the detection scheme works. However there
are cases when it can go awry. For example, if you have a panel
without 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, leaving 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
LVDSFixedMode set to false, the detection steps are skipped and the
driver proceeds 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
different than the work for correctly configuring an old-school CRT
anyway, 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.
MULTIHEAD CONFIGURATIONS
The number of independent outputs is dictated by the number of CRTCs
(in X parlance) a given chip supports. Most recent Intel chips have
two CRTCs, meaning that two separate framebuffers can be displayed
simultaneously, in an extended desktop configuration. If a chip
supports more outputs than it has CRTCs (say local flat panel, VGA and
TV in the case of many outputs), two of the outputs will have to be
"cloned", meaning that they display the same framebuffer contents (or
one displays a subset of another’s framebuffer if the modes aren’t
equal).
You can use the "xrandr" tool, or various desktop utilities, to change
your output configuration at runtime. To statically configure your
outputs, you can use the "Monitor-<type>" options along with additional
monitor sections in your xorg.conf to create your screen topology. The
example below puts the VGA output to the right of the builtin laptop
screen, both running at 1024x768.
Section "Monitor"
Identifier "Laptop FooBar Internal Display"
Option "Position" "0 0"
EndSection
Section "Monitor"
Identifier "Some Random CRT"
Option "Position" "1024 0"
Option "RightOf" "Laptop FoodBar Internal Display"
EndSection
Section "Device"
Driver "intel"
Option "monitor-LVDS" "Laptop FooBar Internal Display"
Option "monitor-VGA" "Some Random CRT"
EndSection
REPORTING BUGS
The xf86-video-intel driver is part of the X.Org and Freedesktop.org
umbrella projects. Details on bug reporting can be found at
http://www.intellinuxgraphics.org/how_to_report_bug.html. Mailing
lists are also commonly used to report experiences and ask questions
about configuration and other topics. See lists.freedesktop.org for
more information (the xorg@lists.freedesktop.org mailing list is the
most appropriate place to ask X.Org and driver related questions).
SEE ALSO
Xorg(1), xorg.conf(5), Xserver(1), X(7)
AUTHORS
Authors include: Keith Whitwell, and also Jonathan Bian, Matthew J
Sottek, 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.