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c496fa1fff
Unmask, then enable interrupts, then enable interrupt sources; matches PCH ordering. The old way (sources, enable, unmask) gives a window during which interrupt conditions would appear in ISR but would never reach IIR and thus never raise an IRQ. Since interrupts only trigger on rising edges in ISR, this would lead to conditions where (for example) output hotplugging would never fire an interrupt because it was already stuck on in ISR. Also, since we know IIR and PIPExSTAT have been cleared during irq_preinstall, don't clear them again during irq_postinstall, nothing good can come of that. Signed-off-by: Adam Jackson <ajax@redhat.com> 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/ *
************************************************************
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