We need it to restore the ilk rc6 context, since the gpu wait no
requires interrupts. But in general having interrupts around should
help in code sanity, since more and more stuff is interrupt driven.
This regression has been introduced in
commit 3e9605018a
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue Nov 27 16:22:54 2012 +0000
drm/i915: Rearrange code to only have a single method for waiting upon the ring
Like in the driver load code we need to make sure that hotplug
interrupts don't cause havoc with our modeset state, hence block them
with the existing infrastructure. Again we ignore races where we might
loose hotplug interrupts ...
Note that the driver load part of the regression has already been
fixed in
commit 52d7ecedac
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Sat Dec 1 21:03:22 2012 +0100
drm/i915: reorder setup sequence to have irqs for output setup
v2: Add a note to the commit message about which patch fixed the
driver load part of the regression. Stable kernels need to backport
both patches.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=54691
Cc: stable@vger.kernel.org (for 3.8 only, plese backport
52d7ecedac first)
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reported-and-Tested-by: Ilya Tumaykin <itumaykin@gmail.com>
Reviewed-by: Chris wilson <chris@chris-wilson.co.uk> (v1)
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
15239099d7