Files
linux/drivers/gpu/drm
Ville Syrjälä 4a3436e85c drm/i915: Shuffle fifo underrun disable/enable points for gmch platforms
Gen2 reports FIFO underruns whenever no planes are enabled on the pipe.
So in order to avoid false positives we must enable the FIFO underrun
reporting only when at least one plane is enabled on the pipe. For
now just move the underrun reporting enable/disable points to the
other side of the plane enable/disable point. That doesn't cover cases
when we turn off all the planes for the pipe but leave the pipe running
on purpose, but it's better than the current situation.

On gen4+ we can actually move the underrun reporting enable/disable to
the opposite ends of the crtc enable/disable hooks. I suppose in theory
we could leave the underrun reporting enabled all the time, except on
VLV where PIPESTAT stops working when the display power well is down.
If we ever get around to unifying the PIPESTAT irq handling for all
gmch platforms, we should still follow the VLV route for other platforms.
It would also micro-optimize the irq handler a bit since we could then
skip the PIPESTAT reads for all disabled pipes.

Gen3 is still a mystery, but for now I'm going to assume it behaves
like gen4+.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Thomas Wood <thomas.wood@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-05-22 15:06:31 +02:00
..
2014-04-22 15:39:11 +02:00
2014-04-29 12:33:46 +02:00
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2014-04-23 10:32:54 +02:00
2014-03-24 00:36:37 +09:00

************************************************************
* 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