diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index baac35f698f9..6571044c9286 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1165,8 +1165,6 @@ skl_dram_get_channels_info(struct drm_i915_private *dev_priv)
 		return -EINVAL;
 	}
 
-	dram_info->valid_dimm = true;
-
 	/*
 	 * If any of the channel is single rank channel, worst case output
 	 * will be same as if single rank memory, so consider single rank
@@ -1183,8 +1181,7 @@ skl_dram_get_channels_info(struct drm_i915_private *dev_priv)
 		return -EINVAL;
 	}
 
-	if (ch0.is_16gb_dimm || ch1.is_16gb_dimm)
-		dram_info->is_16gb_dimm = true;
+	dram_info->is_16gb_dimm = ch0.is_16gb_dimm || ch1.is_16gb_dimm;
 
 	dev_priv->dram_info.symmetric_memory = intel_is_dram_symmetric(val_ch0,
 								       val_ch1,
@@ -1304,7 +1301,6 @@ bxt_get_dram_info(struct drm_i915_private *dev_priv)
 		return -EINVAL;
 	}
 
-	dram_info->valid_dimm = true;
 	dram_info->valid = true;
 	return 0;
 }
@@ -1317,12 +1313,17 @@ intel_get_dram_info(struct drm_i915_private *dev_priv)
 	int ret;
 
 	dram_info->valid = false;
-	dram_info->valid_dimm = false;
-	dram_info->is_16gb_dimm = false;
 	dram_info->rank = I915_DRAM_RANK_INVALID;
 	dram_info->bandwidth_kbps = 0;
 	dram_info->num_channels = 0;
 
+	/*
+	 * Assume 16Gb DIMMs are present until proven otherwise.
+	 * This is only used for the level 0 watermark latency
+	 * w/a which does not apply to bxt/glk.
+	 */
+	dram_info->is_16gb_dimm = !IS_GEN9_LP(dev_priv);
+
 	if (INTEL_GEN(dev_priv) < 9 || IS_GEMINILAKE(dev_priv))
 		return;
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 22cf3c75558c..2d7761b8ac07 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1933,7 +1933,6 @@ struct drm_i915_private {
 
 	struct dram_info {
 		bool valid;
-		bool valid_dimm;
 		bool is_16gb_dimm;
 		u8 num_channels;
 		enum dram_rank {
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 7b49b3c2f9e9..688298cf1aaf 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2881,8 +2881,7 @@ static void intel_read_wm_latency(struct drm_i915_private *dev_priv,
 		 * any underrun. If not able to get Dimm info assume 16GB dimm
 		 * to avoid any underrun.
 		 */
-		if (!dev_priv->dram_info.valid_dimm ||
-		    dev_priv->dram_info.is_16gb_dimm)
+		if (dev_priv->dram_info.is_16gb_dimm)
 			wm[0] += 1;
 
 	} else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {