This fixes a regression introduced in
commit e5868a318d
Author: Egbert Eich <eich@suse.de>
Date: Thu Feb 28 04:17:12 2013 -0500
DRM/i915: Convert HPD interrupts to make use of HPD pin assignment in encode
Due to the irq setup rework in 3.9, see
commit 20afbda209
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Dec 11 14:05:07 2012 +0100
drm/i915: Fixup hpd irq register setup ordering
Egbert Eich's hpd rework blows up on pch-split platforms - it walks
the encoder list before that has been set up completely. The new init
sequence is:
1. irq enabling
2. modeset init
3. hpd setup
We need to move around the ibx setup a bit to fix this.
Ville Syrjälä pointed out in his review that we can't touch SDEIER
after the interrupt handler is set up, since that'll race with Paulo
Zanoni's PCH interrupt race fix:
commit 44498aea29
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date: Fri Feb 22 17:05:28 2013 -0300
drm/i915: also disable south interrupts when handling them
We fix that by unconditionally enabling all interrupts in SDEIER, but
masking them as-needed in SDEIMR. Since only the single-threaded
setup/teardown (or suspend/resume) code touches that, no further
locking is required.
While at it also simplify the mask handling - we start out with all
interrupts cleared in the postinstall hook, and never enable a hpd
interrupt before hpd_irq_setup is called.
And finally, for consistency rename the ibx hpd setup function to
ibx_hpd_irq_setup.
v2: Fix race around SDEIER writes (Ville).
v3: Remove the superflous posting read for SDEIER, spotted by Ville.
Ville also wondered whether we shouldn't clear SDEIIR, since now
SDE interrupts are enabled before we have an irq handler installed.
But the master interrupt control bit in DEIER is still cleared, so we
should be fine.
Cc: Egbert Eich <eich@suse.de>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=62798
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
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
82a28bcf56