From: kettenis <kettenis@openbsd.org>
Date: Sun, 18 Oct 2015 18:00:45 +0000 (+0000)
Subject: Backport another Broadwell fix from Linux 3.15
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=114eafaa6aa4e9cde5e92abfe4beb37584b7096d;p=openbsd

Backport another Broadwell fix from Linux 3.15

Ben Widawsky
drm/i915: Provide PDP updates via MMIO
e178f7057b81c87a7ceaae0ca204487b6f7eedcf

Doesn't make resume work, but at least it prevents the machine from hanging
and/or resetting.
---

diff --git a/sys/dev/pci/drm/i915/i915_gem_gtt.c b/sys/dev/pci/drm/i915/i915_gem_gtt.c
index d2d5d2b767c..9372f974fbb 100644
--- a/sys/dev/pci/drm/i915/i915_gem_gtt.c
+++ b/sys/dev/pci/drm/i915/i915_gem_gtt.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: i915_gem_gtt.c,v 1.13 2015/09/26 13:15:25 kettenis Exp $	*/
+/*	$OpenBSD: i915_gem_gtt.c,v 1.14 2015/10/18 18:00:45 kettenis Exp $	*/
 /*
  * Copyright © 2010 Daniel Vetter
  *
@@ -209,12 +209,19 @@ static gen6_gtt_pte_t iris_pte_encode(dma_addr_t addr,
 
 /* Broadwell Page Directory Pointer Descriptors */
 static int gen8_write_pdp(struct intel_ring_buffer *ring, unsigned entry,
-			   uint64_t val)
+			   uint64_t val, bool synchronous)
 {
+	struct drm_i915_private *dev_priv = ring->dev->dev_private;
 	int ret;
 
 	BUG_ON(entry >= 4);
 
+	if (synchronous) {
+		I915_WRITE(GEN8_RING_PDP_UDW(ring, entry), val >> 32);
+		I915_WRITE(GEN8_RING_PDP_LDW(ring, entry), (u32)val);
+		return 0;
+	}
+
 	ret = intel_ring_begin(ring, 6);
 	if (ret)
 		return ret;
@@ -248,7 +255,8 @@ static int gen8_ppgtt_enable(struct drm_device *dev)
 	for (i = used_pd - 1; i >= 0; i--) {
 		dma_addr_t addr = ppgtt->pd_dma_addr[i];
 		for_each_ring(ring, dev_priv, j) {
-			ret = gen8_write_pdp(ring, i, addr);
+			ret = gen8_write_pdp(ring, i, addr,
+					     i915_reset_in_progress(&dev_priv->gpu_error));
 			if (ret)
 				goto err_out;
 		}