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dff33cfcef
I discovered several bugs in the FIFO code that was recently applied. Some of them fell into the "how did this ever work" category, since in some cases we were using the wrong FIFO size values, and the calculations ended up being way off. This patch fixes all the bugs I found, and works well on my GM45, 915GM and 855GM test machines; but as usual with these sorts of patches broader testing is definitely requested (in particular this patch affects 830, 845 and 865 for which I don't have test hardware). Overall, the patch clarifies the watermark calculation function by adding some comments and debug info, and making the variable names a bit clearer. The "get FIFO size" portion of the code has also been corrected, so we should be able to properly detect the FIFO allocations for each pipe, for use in the watermark calculation. Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Eric Anholt <eric@anholt.net>
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* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
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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