[ 3.5.y.z extended stable ] Patch "drm/i915: GFX_MODE Flush TLB Invalidate Mode must be '1' for" has been added to staging queue

[Herton Ronaldo Krzesinski]

This is a note to let you know that I have just added a patch titled

    drm/i915: GFX_MODE Flush TLB Invalidate Mode must be '1' for

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From ca580ba69e5f2a6e5d4c57e4c95c2bc06cd57db4 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris at chris-wilson.co.uk>
Date: Sun, 20 Jan 2013 16:33:32 +0000
Subject: [PATCH] drm/i915: GFX_MODE Flush TLB Invalidate Mode must be '1' for
 scanline waits

commit f05bb0c7b624252a5e768287e340e8e45df96e42 upstream.

On SNB, if bit 13 of GFX_MODE, Flush TLB Invalidate Mode, is not set to 1,
the hardware can not program the scanline values. Those scanline values
then control when the signal is sent from the display engine to the render
ring for MI_WAIT_FOR_EVENTs. Note setting this bit means that TLB
invalidations must be performed explicitly through the appropriate bits
being set in PIPE_CONTROL.

References: https://bugzilla.kernel.org/show_bug.cgi?id=52311
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Ben Widawsky <ben at bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/gpu/drm/i915/intel_ringbuffer.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 78486c7..e75d794 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -421,6 +421,11 @@ static int init_render_ring(struct intel_ring_buffer *ring)
 	if (INTEL_INFO(dev)->gen >= 6)
 		I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(ASYNC_FLIP_PERF_DISABLE));

+	/* Required for the hardware to program scanline values for waiting */
+	if (INTEL_INFO(dev)->gen == 6)
+		I915_WRITE(GFX_MODE,
+			   _MASKED_BIT_ENABLE(GFX_TLB_INVALIDATE_ALWAYS));
+
 	if (IS_GEN7(dev))
 		I915_WRITE(GFX_MODE_GEN7,
 			   _MASKED_BIT_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) |
--
1.7.9.5