652c393a33
There are several sources of unnecessary power consumption on Intel graphics systems. The first is the LVDS clock. TFTs don't suffer from persistence issues like CRTs, and so we can reduce the LVDS refresh rate when the screen is idle. It will be automatically upclocked when userspace triggers graphical activity. Beyond that, we can enable memory self refresh. This allows the memory to go into a lower power state when the graphics are idle. Finally, we can drop some clocks on the gpu itself. All of these things can be reenabled between frames when GPU activity is triggered, and so there should be no user visible graphical changes. Signed-off-by: Jesse Barnes <jesse.barnes@intel.com> Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Eric Anholt <eric@anholt.net>
************************************************************ * 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