diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index ce52030bf71d802c1a3f102539ef4e45d11245c9..7c899984b0d4289518d08e95a0c446255903714f 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -213,6 +213,7 @@ __intel_engine_context_size(struct drm_i915_private *dev_priv, u8 class)
 			return round_up(GEN6_CXT_TOTAL_SIZE(cxt_size) * 64,
 					PAGE_SIZE);
 		case 5:
+		case 4:
 			/*
 			 * There is a discrepancy here between the size reported
 			 * by the register and the size of the context layout
@@ -229,7 +230,6 @@ __intel_engine_context_size(struct drm_i915_private *dev_priv, u8 class)
 					 cxt_size * 64,
 					 cxt_size - 1);
 			return round_up(cxt_size * 64, PAGE_SIZE);
-		case 4:
 		case 3:
 		case 2:
 		/* For the special day when i810 gets merged. */
diff --git a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
index 875dd458c44710e88e8535d9d298f529187110e5..4afb19e7c6477a892ef5336ea7a0efc74cb5ee45 100644
--- a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
@@ -834,6 +834,20 @@ static int rcs_resume(struct intel_engine_cs *engine)
 {
 	struct drm_i915_private *dev_priv = engine->i915;
 
+	/*
+	 * Disable CONSTANT_BUFFER before it is loaded from the context
+	 * image. For as it is loaded, it is executed and the stored
+	 * address may no longer be valid, leading to a GPU hang.
+	 *
+	 * This imposes the requirement that userspace reload their
+	 * CONSTANT_BUFFER on every batch, fortunately a requirement
+	 * they are already accustomed to from before contexts were
+	 * enabled.
+	 */
+	if (IS_GEN(dev_priv, 4))
+		I915_WRITE(ECOSKPD,
+			   _MASKED_BIT_ENABLE(ECO_CONSTANT_BUFFER_SR_DISABLE));
+
 	/* WaTimedSingleVertexDispatch:cl,bw,ctg,elk,ilk,snb */
 	if (IS_GEN_RANGE(dev_priv, 4, 6))
 		I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(VS_TIMER_DISPATCH));
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b74824f0b5b1fcbc17262bc17e85238e88b2ceb3..6f0a0866c8024e69da5d364f6eeb710b46058c29 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2870,6 +2870,7 @@ enum i915_power_well_id {
 #define GFX_FLSH_CNTL_GEN6	_MMIO(0x101008)
 #define   GFX_FLSH_CNTL_EN	(1 << 0)
 #define ECOSKPD		_MMIO(0x21d0)
+#define   ECO_CONSTANT_BUFFER_SR_DISABLE REG_BIT(4)
 #define   ECO_GATING_CX_ONLY	(1 << 3)
 #define   ECO_FLIP_DONE		(1 << 0)