Patch "drm/i915: Perform an invalidate prior to executing golden renderstate" has been added to the 4.12-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    drm/i915: Perform an invalidate prior to executing golden renderstate

to the 4.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-perform-an-invalidate-prior-to-executing-golden-renderstate.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From a0125a932e917cb507b682cb66645efdca1f8cab Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 8 Aug 2017 14:19:04 +0100
Subject: drm/i915: Perform an invalidate prior to executing golden renderstate

From: Chris Wilson <chris@chris-wilson.co.uk>

commit a0125a932e917cb507b682cb66645efdca1f8cab upstream.

As we may have just bound the renderstate into the GGTT for execution, we
need to ensure that the GTT TLB are also flushed.

On snb-gt2, this would cause a random GPU hang at the start of a new
context (e.g. boot) and on snb-gt1, it was causing the renderstate batch
to take ~10s. It was the GPU hang that revealed the truth, as the CS
gleefully executed beyond the end of the golden renderstate batch, a good
indicator for a GTT TLB miss.

Fixes: 20fe17aa52dc ("drm/i915: Remove redundant TLB invalidate on switching contexts")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170808131904.1385-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: <drm-intel-fixes@lists.freedesktop.org> # v4.12-rc1+
(cherry picked from commit 802673d66f8a6ded5d2689d597853c7bb3a70163)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/i915_gem_render_state.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/i915/i915_gem_render_state.c
+++ b/drivers/gpu/drm/i915/i915_gem_render_state.c
@@ -242,6 +242,10 @@ int i915_gem_render_state_emit(struct dr
 			goto err_unpin;
 	}
 
+	ret = req->engine->emit_flush(req, EMIT_INVALIDATE);
+	if (ret)
+		goto err_unpin;
+
 	ret = req->engine->emit_bb_start(req,
 					 so->batch_offset, so->batch_size,
 					 I915_DISPATCH_SECURE);


Patches currently in stable-queue which might be from chris@chris-wilson.co.uk are

queue-4.12/drm-i915-perform-an-invalidate-prior-to-executing-golden-renderstate.patch