linux/include
Dave Airlie ebff5fa9d5 Revert "i915: Update VGA arbiter support for newer devices"
This reverts commit 81b5c7bc8d.

Adding drm/i915 into the vga arbiter chain means that X (in a piece of
well-meant paranoia) will do a get/put on the vga decoding around
_every_ accel call down into the ddx. Which results in some nice
performance disasters [1]. This really breaks userspace, by disabling
DRI for everyone, and stops OpenGL from working, this isn't limited
to just the i915 but both the integrated and discrete GPUs on
multi-gpu systems, in other words this causes untold worlds of pain,

Ville tried to come up with a Great Hack to fiddle the required VGA
I/O ops behind everyone's back using stop_machine, but that didn't
really work out [2]. Given that we're fairly late in the -rc stage for
such games let's just revert this all.

One thing we might want to keep is to delay the disabling of the vga
decoding until the fbdev emulation and the fbcon screen is set up. If
we kill vga mem decoding beforehand fbcon can end up with a white
square in the top-left corner it tried to save from the vga memory for
a seamless transition. And we have bug reports on older platforms
which seem to match these symptoms.

But again that's something to play around with in -next.

References: [1] http://lists.x.org/archives/xorg-devel/2013-September/037763.html
References: [2] http://www.spinics.net/lists/intel-gfx/msg34062.html
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-10-11 15:19:22 +10:00
..
acpi
asm-generic mm: Fix generic hugetlb pte check return type. 2013-10-02 20:02:35 -04:00
clocksource
crypto
drm Revert "drm: mark context support as a legacy subsystem" 2013-09-20 08:32:59 +10:00
dt-bindings Device tree core updates for v3.12 2013-09-10 13:53:52 -07:00
keys
kvm
linux Revert "i915: Update VGA arbiter support for newer devices" 2013-10-11 15:19:22 +10:00
math-emu
media
memory
misc
net Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2013-10-01 12:39:35 -04:00
pcmcia
ras
rdma
rxrpc
scsi Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2013-09-12 16:11:45 -07:00
sound sound fixes for 3.12-rc1 2013-09-12 08:52:41 -07:00
target target/iscsi: Bump versions to v4.1.0 2013-09-10 20:23:37 -07:00
trace Merge branch 'for-3.12/core' of git://git.kernel.dk/linux-block 2013-09-22 15:00:11 -07:00
uapi Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux 2013-09-29 10:02:40 -07:00
video
xen
Kbuild