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Daniel Vetter
e2e1ed41ed
This is definetely a bit more generic than currently required, but if we keep track of all crtcs that need to be disabled/enable (because they loose an encoder or something similar), crtcs that get completely disabled and those that we need to do an actual mode change nicely prepares us for global modeset operations on multiple crtcs. The only big thing missing here would be a global resource allocation step (for e.g. pch plls), which would equally frob these bitmasks if e.g. a crtc only needs a new pll. Or if we need to enable dithering on an another pipe due to bandwidth constrains somewhere. These masks aren't yet put to use in this patch, this will follow in the next one. v2-v5: Fix up the computations for good (hopefully). v6: Fixup a confusion reported by Damien Lespiau: I've conserved the (imo braindead) behaviour of the crtc helper to disable _any_ disconnected outputs if we do a modeset, even when that newly disabled connector isn't connected to the crtc being changed by the modeset. The effect of that is that we could disable an arbitrary number of unrelated crtcs, which I haven't taken into account when writing this code. Fix this up. Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> 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