Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

1 files changed, 40 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 245f0022bcfd..3fe358db1276 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2493,6 +2493,9 @@ static uint32_t ilk_compute_pri_wm(const struct intel_crtc_state *cstate,
         uint32_t method1, method2;
         int cpp;
 
+        if (mem_value == 0)
+                return U32_MAX;
+
         if (!intel_wm_plane_visible(cstate, pstate))
                 return 0;
 
@@ -2522,6 +2525,9 @@ static uint32_t ilk_compute_spr_wm(const struct intel_crtc_state *cstate,
         uint32_t method1, method2;
         int cpp;
 
+        if (mem_value == 0)
+                return U32_MAX;
+
         if (!intel_wm_plane_visible(cstate, pstate))
                 return 0;
 
@@ -2545,6 +2551,9 @@ static uint32_t ilk_compute_cur_wm(const struct intel_crtc_state *cstate,
 {
         int cpp;
 
+        if (mem_value == 0)
+                return U32_MAX;
+
         if (!intel_wm_plane_visible(cstate, pstate))
                 return 0;
 
@@ -3008,6 +3017,34 @@ static void snb_wm_latency_quirk(struct drm_i915_private *dev_priv)
         intel_print_wm_latency(dev_priv, "Cursor", dev_priv->wm.cur_latency);
 }
 
+static void snb_wm_lp3_irq_quirk(struct drm_i915_private *dev_priv)
+{
+        /*
+         * On some SNB machines (Thinkpad X220 Tablet at least)
+         * LP3 usage can cause vblank interrupts to be lost.
+         * The DEIIR bit will go high but it looks like the CPU
+         * never gets interrupted.
+         *
+         * It's not clear whether other interrupt source could
+         * be affected or if this is somehow limited to vblank
+         * interrupts only. To play it safe we disable LP3
+         * watermarks entirely.
+         */
+        if (dev_priv->wm.pri_latency[3] == 0 &&
+            dev_priv->wm.spr_latency[3] == 0 &&
+            dev_priv->wm.cur_latency[3] == 0)
+                return;
+
+        dev_priv->wm.pri_latency[3] = 0;
+        dev_priv->wm.spr_latency[3] = 0;
+        dev_priv->wm.cur_latency[3] = 0;
+
+        DRM_DEBUG_KMS("LP3 watermarks disabled due to potential for lost interrupts\n");
+        intel_print_wm_latency(dev_priv, "Primary", dev_priv->wm.pri_latency);
+        intel_print_wm_latency(dev_priv, "Sprite", dev_priv->wm.spr_latency);
+        intel_print_wm_latency(dev_priv, "Cursor", dev_priv->wm.cur_latency);
+}
+
 static void ilk_setup_wm_latency(struct drm_i915_private *dev_priv)
 {
         intel_read_wm_latency(dev_priv, dev_priv->wm.pri_latency);
@@ -3024,8 +3061,10 @@ static void ilk_setup_wm_latency(struct drm_i915_private *dev_priv)
         intel_print_wm_latency(dev_priv, "Sprite", dev_priv->wm.spr_latency);
         intel_print_wm_latency(dev_priv, "Cursor", dev_priv->wm.cur_latency);
 
-        if (IS_GEN6(dev_priv))
+        if (IS_GEN6(dev_priv)) {
                 snb_wm_latency_quirk(dev_priv);
+                snb_wm_lp3_irq_quirk(dev_priv);
+        }
 }
 
 static void skl_setup_wm_latency(struct drm_i915_private *dev_priv)