We want to enable/disable display IRQs only if global i915 IRQs are
enabled. To check the latter it's not enough to consult the DRM
dev->irq_enabled flag, since runtime PM can disable/enable IRQs
and it won't adjust this flag only the i915 specific
dev_priv->pm._irqs_disabled flag. Fix this by using the proper
intel_irqs_enabled() helper instead.
Fortunately this didn't cause an actual problem since even if we enabled
display IRQs too early (before enabling global i915 IRQs) the
VLV_MASTER_IER would still be clear masking all IRQs.
This issue was caught by
commit 920dd15a2b2fc60d054646a8a1ffd6aeb6090e05
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Wed Aug 27 10:43:37 2014 +0200
drm/i915: WARN if interrupts aren't on in en/disable_pipestat
Signed-off-by: Imre Deak <imre.deak@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
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
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