The BIOS or boot loader will generally create an initial display
configuration for us that includes some set of active pipes and
displays. This routine tries to figure out which pipes and connectors
are active and stuffs them into the crtcs and modes array given to us by
the drm_fb_helper code.
The overall sequence is:
intel_fbdev_init - from driver load
intel_fbdev_init_bios - initialize the intel_fbdev using BIOS data
drm_fb_helper_init - build fb helper structs
drm_fb_helper_single_add_all_connectors - more fb helper structs
intel_fbdev_initial_config - apply the config
drm_fb_helper_initial_config - call ->probe then register_framebuffer()
drm_setup_crtcs - build crtc config for fbdev
intel_fb_initial_config - find active connectors etc
drm_fb_helper_single_fb_probe - set up fbdev
intelfb_create - re-use or alloc fb, build out fbdev structs
v2: use BIOS connector config unconditionally if possible (Daniel)
check for crtc cloning and reject (Daniel)
fix up comments (Daniel)
v3: use command line args and preferred modes first (Ville)
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Re-add the WARN_ON for a missing encoder crtc - the state
sanitizer should take care of this. And spell-ocd the comments.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
************************************************************
* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
************************************************************
The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).
The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:
1. The DRM provides synchronized access to the graphics hardware via
the use of an optimized two-tiered lock.
2. The DRM enforces the DRI security policy for access to the graphics
hardware by only allowing authenticated X11 clients access to
restricted regions of memory.
3. The DRM provides a generic DMA engine, complete with multiple
queues and the ability to detect the need for an OpenGL context
switch.
4. The DRM is extensible via the use of small device-specific modules
that rely extensively on the API exported by the DRM module.
Documentation on the DRI is available from:
http://dri.freedesktop.org/wiki/Documentation
http://sourceforge.net/project/showfiles.php?group_id=387
http://dri.sourceforge.net/doc/
For specific information about kernel-level support, see:
The Direct Rendering Manager, Kernel Support for the Direct Rendering
Infrastructure
http://dri.sourceforge.net/doc/drm_low_level.html
Hardware Locking for the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/hardware_locking_low_level.html
A Security Analysis of the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/security_low_level.html
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