[Intel-gfx] [PATCH] drmmode: unreserve userspace fences

[Daniel Vetter]

With drmmode, the kernel should control all fence regs. Fence
starved i8xx with tiled glyph caches actually managed to max out the
5 fences available by default: 1 target, 4 glyph cache bos + one
used by kms modeset for scanout.

Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 src/drmmode_display.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/src/drmmode_display.c b/src/drmmode_display.c
index b1dee76..7dfc4b3 100644
--- a/src/drmmode_display.c
+++ b/src/drmmode_display.c
@@ -1384,6 +1384,7 @@ Bool drmmode_pre_init(ScrnInfoPtr scrn, int fd, int cpp)
 {
 	xf86CrtcConfigPtr   xf86_config;
 	drmmode_ptr drmmode;
+	struct drm_i915_setparam sp;
 	int i;
 
 	drmmode = xnfalloc(sizeof *drmmode);
@@ -1410,6 +1411,11 @@ Bool drmmode_pre_init(ScrnInfoPtr scrn, int fd, int cpp)
 		drmmode_output_init(scrn, drmmode, i);
 
 	xf86InitialConfiguration(scrn, TRUE);
+	/* Kernel does all the tiled buffer fencing for us. */
+	sp.param = I915_SETPARAM_NUM_USED_FENCES;
+	sp.value = 0;
+	drmCommandWrite(drmmode->fd, DRM_I915_SETPARAM,
+			      &sp, sizeof(sp));
 
 	return TRUE;
 }
-- 
1.6.6