drm/i915: Revert i915.semaphore=1 default from 47ae63e0

My Q67 / i7-2600 box has rev09 Sandy Bridge graphics.  It hangs
instantly when GNOME loads and it hangs so hard the reset button
doesn't work.  Setting i915.semaphore=0 fixes it.

Semaphores were disabled in a1656b9090f7008d2941c314f5a64724bea2ae37
in 2.6.38 and were re-enabled by

commit 47ae63e0c2e5fdb582d471dc906eb29be94c732f
Merge: c59a333 467cffb
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Mar 7 12:32:44 2011 +0000

    Merge branch 'drm-intel-fixes' into drm-intel-next

    Apply the trivial conflicting regression fixes, but keep GPU semaphores
    enabled.

    Conflicts:
        drivers/gpu/drm/i915/i915_drv.h
        drivers/gpu/drm/i915/i915_gem_execbuffer.c

(It's worth noting that the offending change is i915_drv.c,
 which is not a conflict.)

Signed-off-by: Andy Lutomirski <luto@mit.edu>
Acked-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index c34a8dd..32d1b3e 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -49,7 +49,7 @@ module_param_named(panel_ignore_lid, i915_panel_ignore_lid, int, 0600);
 unsigned int i915_powersave = 1;
 module_param_named(powersave, i915_powersave, int, 0600);
 
-unsigned int i915_semaphores = 1;
+unsigned int i915_semaphores = 0;
 module_param_named(semaphores, i915_semaphores, int, 0600);
 
 unsigned int i915_enable_rc6 = 0;