Intel graphics: Difference between revisions
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=== Enable early KMS === | === Enable early KMS === | ||
[[Kernel mode setting]] (KMS) is supported by Intel chipsets that use the i915 DRM driver and is mandatory and enabled by default. | |||
[[ | Refer to [[Kernel_mode_setting#Early_KMS_start]] for instuctions on how to enable KMS as soon as possible at the boot process. | ||
== Module-based Powersaving Options == | == Module-based Powersaving Options == |
Revision as of 11:02, 15 July 2016
zh-cn:Intel graphics zh-tw:Intel graphics
Since Intel provides and supports open source drivers, Intel graphics are essentially plug-and-play.
For a comprehensive list of Intel GPU models and corresponding chipsets and CPUs, see this comparison on Wikipedia.
- Some recommend not installing the Intel driver, and instead falling back on the modesetting driver. See [1], [2], Xorg#Installation, and
man modesetting
. - PowerVR-based graphics (GMA 500 and GMA 3600 series) are not supported by open source drivers.
Installation
Install the xf86-video-intel package. It provides the DDX driver for 2D acceleration and it pulls in mesa as a dependency, providing the DRI driver for 3D acceleration.
To enable OpenGL support, also install mesa-libgl. If you are on x86_64 and need 32-bit support, also install lib32-mesa-libgl from the multilib repository.
Also see Hardware video acceleration.
For Vulkan support, install vulkan-intel on Ivy-Bridge or newer GPUs.
Configuration
There is no need for any configuration to run Xorg.
However, to take advantage of some driver options, you will need to create a Xorg configuration file similar to the one below:
/etc/X11/xorg.conf.d/20-intel.conf
Section "Device" Identifier "Intel Graphics" Driver "intel" EndSection
Additional options are added by the user on new lines below Driver
.
- You may need to indicate
Option "AccelMethod"
when creating a configuration file, even just to set it to the default method (currently"sna"
); otherwise, X may crash. - You might need to add more device sections than the one listed above. This will be indicated where necessary.
For the full list of options, see the man page for intel
.
Loading
The Intel kernel module should load fine automatically on system boot.
If it does not happen, then:
- Make sure you do not have
nomodeset
orvga=
as a kernel parameter, since Intel requires kernel mode-setting. - Also, check that you have not disabled Intel by using any modprobe blacklisting within
/etc/modprobe.d/
or/usr/lib/modprobe.d/
.
Enable early KMS
Kernel mode setting (KMS) is supported by Intel chipsets that use the i915 DRM driver and is mandatory and enabled by default.
Refer to Kernel_mode_setting#Early_KMS_start for instuctions on how to enable KMS as soon as possible at the boot process.
Module-based Powersaving Options
The i915
kernel module allows for configuration via module options. Some of the module options impact power saving.
A list of all options along with short descriptions and default values can be generated with the following command:
$ modinfo -p i915
To check which options are currently enabled, run
# systool -m i915 -av
You will note that the i915.powersave
option which "enable[s] powersavings, fbc, downclocking, etc." is enabled by default, resulting in per-chip powersaving defaults. It is however possible to configure more aggressive powersaving by using module options.
The following set of options should be generally safe to enable:
/etc/modprobe.d/i915.conf
options i915 enable_rc6=1 enable_fbc=1 lvds_downclock=1 semaphores=1
RC6 sleep modes (enable_rc6)
You can experiment with higher values for enable_rc6
, but your GPU may not support them or the activation of the other options [3].
The available enable_rc6
values are a bitmask with bit values RC6=1, RC6p=2, RC6pp=3[4] - where "RC6p" and "RC6pp" are lower power states.
To confirm the current running RC6 level, you can look in sysfs:
# cat /sys/class/drm/card0/power/rc6_enable
... if the value read is a lower number than expected, the other RC6 level are probably not supported. Passing drm.debug=0xe
will add DRM debugging information to the kernel log - possibly including a line like this:
[drm:sanitize_rc6_option] Adjusting RC6 mask to 1 (requested 7, valid 1)
Framebuffer compression (enable_fbc)
Framebuffer compression may be unreliable or unavailable on Intel GPU generations before Sandy Bridge (generation 6). This results in messages logged to the system journal similar to this one:
kernel: drm: not enough stolen space for compressed buffer, disabling.
Tips and tricks
Tear-free video
The SNA acceleration method causes tearing for some people. To fix this, enable the "TearFree"
option in the driver by adding the following line to your configuration file:
Option "TearFree" "true"
See the original bug report for more info.
- This option may not work when
SwapbuffersWait
isfalse
. - This option is problematic for applications that are very picky about vsync timing, like Super Meat Boy.
- This option does not work with UXA acceleration method, only with SNA.
- This option should not be needed with DRI3 enabled.
Disable Vertical Synchronization (VSYNC)
The intel-driver uses Triple Buffering for vertical synchronization, this allows for full performance and avoids tearing. To turn vertical synchronization off (e.g. for benchmarking) use this .drirc
in your home directory:
~/.drirc
<device screen="0" driver="dri2"> <application name="Default"> <option name="vblank_mode" value="0"/> </application> </device>
Setting scaling mode
This can be useful for some full screen applications:
$ xrandr --output LVDS1 --set PANEL_FITTING param
where param
can be:
center
: resolution will be kept exactly as defined, no scaling will be made,full
: scale the resolution so it uses the entire screen orfull_aspect
: scale the resolution to the maximum possible but keep the aspect ratio.
If it does not work, try:
$ xrandr --output LVDS1 --set "scaling mode" param
where param
is one of "Full"
, "Center"
or "Full aspect"
.
KMS Issue: console is limited to small area
One of the low-resolution video ports may be enabled on boot which is causing the terminal to utilize a small area of the screen. To fix, explicitly disable the port with an i915 module setting with video=SVIDEO-1:d
in the kernel command line parameter in the bootloader. See Kernel parameters for more info.
If that does not work, try disabling TV1 or VGA1 instead of SVIDEO-1.
H.264 decoding on GMA 4500
The libva-intel-driver package provides MPEG-2 decoding only for GMA 4500 series GPUs. The H.264 decoding support is maintained in a separated g45-h264 branch, which can be used by installing libva-intel-driver-g45-h264AUR package. Note however that this support is experimental and its development has been abandoned. Using the VA-API with this driver on a GMA 4500 series GPU will offload the CPU but may not result in as smooth a playback as non-accelerated playback. Tests using mplayer showed that using vaapi to play back an H.264 encoded 1080p video halved the CPU load (compared to the XV overlay) but resulted in very choppy playback, while 720p worked reasonably well [5]. This is echoed by other experiences [6]. Setting the preallocated video ram size higher in bios results in much better hardware decoded playback. Even 1080p h264 works well if this is done.
Setting brightness and gamma
See Backlight.
Troubleshooting
SNA issues
SNA is the default acceleration method in xf86-video-intel. If you are experience issues with SNA (e.g. pixelated graphics, corrupt text, etc.), try using UXA instead, which can be done by adding the following line to your configuration file:
Option "AccelMethod" "uxa"
See man 4 intel
under Option "AccelMethod"
.
Font and screen corruption in GTK+ applications (missing glyphs after suspend/resume)
Should you experience missing font glyphs in GTK+ applications, the following workaround might help. Edit /etc/environment
to add the following line:
/etc/environment
COGL_ATLAS_DEFAULT_BLIT_MODE=framebuffer
See also FreeDesktop bug 88584.
Blank screen during boot, when "Loading modules"
If using "late start" KMS and the screen goes blank when "Loading modules", it may help to add i915
and intel_agp
to the initramfs. See Kernel mode setting#Early KMS start section.
Alternatively, appending the following kernel parameter seems to work as well:
video=SVIDEO-1:d
If you need to output to VGA then try this:
video=VGA-1:1280x800
X freeze/crash with intel driver
Some issues with X crashing, GPU hanging, or problems with X freezing, can be fixed by disabling the GPU usage with the NoAccel
option - add the following lines to your configuration file:
Option "NoAccel" "True"
Alternatively, try to disable the 3D acceleration only with the DRI
option:
Option "DRI" "False"
If you experience crashes and have
Option "TearFree" "true" Option "AccelMethod" "sna"
in your configuration file, in most cases these can be fixed by adding
i915.semaphores=1
to your boot parameters.
If you are using kernel 4.0.X or above on Baytrail architecture and frequently encounter complete system freezes (especially when watching video or using GFX intensivelly), you should try adding the following kernel option as a workaround, until this bug will be fixed permanently.
intel_idle.max_cstate=1
Adding undetected resolutions
This issue is covered on the Xrandr page.
Weathered colors (color range problem)
Kernel 3.9 contains a new default "Automatic" mode for the "Broadcast RGB" property in the Intel driver. It is almost equivalent to "Limited 16:235" (instead of the old default "Full") whenever an HDMI/DP output is in a CEA mode. If a monitor does not support signal in limited color range, it will cause weathered colors.
One can force mode e.g. xrandr --output <HDMI> --set "Broadcast RGB" "Full"
(replace <HDMI>
with the appropriate output device, verify by running xrandr
).
Unfortunately, the Intel driver does not support setting the color range through an xorg.conf.d
configuration file.
A bug report is filed and a patch can be found in the attachment.
Also there are other related problems which can be fixed editing GPU registers. More information can be found [7] and [8].
Backlight is not adjustable
If after resuming from suspend, the hotkeys for changing the screen brightness do not take effect, check your configuration against the Backlight article.
If the problem persists, try one of the following kernel parameters:
acpi_osi=Linux acpi_osi="!Windows 2012" acpi_osi=
Disabling frame buffer compression
Enabling frame buffer compression on pre-Sandy Bridge CPUs results in endless error messages:
$ dmesg |tail [ 2360.475430] [drm] not enough stolen space for compressed buffer (need 4325376 bytes), disabling [ 2360.475437] [drm] hint: you may be able to increase stolen memory size in the BIOS to avoid this
The solution is to disable frame buffer compression which will slightly increase power consumption. In order to disable it add i915.enable_fbc=0
to the kernel line parameters. More information on the results of disabled compression can be found here.
Corruption/Unresponsiveness in Chromium and Firefox
If you experience corruption or unresponsiveness in Chromium and/or Firefox set the AccelMethod to "uxa".
Kernel crashing w/kernels 4.0+ on Broadwell/Core-M chips
A few seconds after X/Wayland loads the machine will freeze and journalctl will log a kernel crash referencing the Intel graphics as below:
Jun 16 17:54:03 hostname kernel: BUG: unable to handle kernel NULL pointer dereference at (null) Jun 16 17:54:03 hostname kernel: IP: [< (null)>] (null) ... Jun 16 17:54:03 hostname kernel: CPU: 0 PID: 733 Comm: gnome-shell Tainted: G U O 4.0.5-1-ARCH #1 ... Jun 16 17:54:03 hostname kernel: Call Trace: Jun 16 17:54:03 hostname kernel: [<ffffffffa055cc27>] ? i915_gem_object_sync+0xe7/0x190 [i915] Jun 16 17:54:03 hostname kernel: [<ffffffffa0579634>] intel_execlists_submission+0x294/0x4c0 [i915] Jun 16 17:54:03 hostname kernel: [<ffffffffa05539fc>] i915_gem_do_execbuffer.isra.12+0xabc/0x1230 [i915] Jun 16 17:54:03 hostname kernel: [<ffffffffa055d349>] ? i915_gem_object_set_to_cpu_domain+0xa9/0x1f0 [i915] Jun 16 17:54:03 hostname kernel: [<ffffffff811ba2ae>] ? __kmalloc+0x2e/0x2a0 Jun 16 17:54:03 hostname kernel: [<ffffffffa0555471>] i915_gem_execbuffer2+0x141/0x2b0 [i915] Jun 16 17:54:03 hostname kernel: [<ffffffffa042fcab>] drm_ioctl+0x1db/0x640 [drm] Jun 16 17:54:03 hostname kernel: [<ffffffffa0555330>] ? i915_gem_execbuffer+0x450/0x450 [i915] Jun 16 17:54:03 hostname kernel: [<ffffffff8122339b>] ? eventfd_ctx_read+0x16b/0x200 Jun 16 17:54:03 hostname kernel: [<ffffffff811ebc36>] do_vfs_ioctl+0x2c6/0x4d0 Jun 16 17:54:03 hostname kernel: [<ffffffff811f6452>] ? __fget+0x72/0xb0 Jun 16 17:54:03 hostname kernel: [<ffffffff811ebec1>] SyS_ioctl+0x81/0xa0 Jun 16 17:54:03 hostname kernel: [<ffffffff8157a589>] system_call_fastpath+0x12/0x17 Jun 16 17:54:03 hostname kernel: Code: Bad RIP value. Jun 16 17:54:03 hostname kernel: RIP [< (null)>] (null)
This can be fixed by disabling execlist support which was changed to default on with kernel 4.0. Add the following kernel parameter:
i915.enable_execlists=0
This is known to be broken to at least kernel 4.0.5.
Skylake support
For linux kernels older than 4.3.x, i915.preliminary_hw_support=1
must be added to your boot parameters for the driver to work on the new Intel Skylake (6th gen.) GPUs. On a fully updated system running kernel 4.3.x and up, this step is unneccesary.
The i915 DRM driver is known to cause various GPU hangs, crashes and even full system freezes. It might be neccesary to disable hardware acceleration to workaround these issues. One solution is to use the following Xorg configuration.
/etc/X11/xorg.conf.d/20-intel.conf
Section "Device" Identifier "Intel Graphics" Driver "intel" Option "DRI" "false" EndSection
Otherwise, specific applications such as Chromium and Firefox browsers can be instructed to disable hardware rendering directly.
Another option that seems to work for some users is to add the i915.enable_rc6=0
kernel boot parameter, which will cause the CPU/GPU to remain in high-power modes, but seems to resolve most cases of GPU hangs and system freezes.
Lag in Windows guests
The video output of a Windows guests in VirtualBox sometimes hangs until the host forces a screen update (e.g. by moving the mouse cursor). Removing the enable_fbc=1
option fixes this issue.
See also
- https://01.org/linuxgraphics/documentation (includes a list of supported hardware)