5 files changed, 26 insertions, 12 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 2909b123baf5..359f6e8b9b00 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -676,6 +676,7 @@ static void i915_ring_error_state(struct seq_file *m,
         seq_printf(m, "  INSTPM: 0x%08x\n", error->instpm[ring]);
         seq_printf(m, "  FADDR: 0x%08x\n", error->faddr[ring]);
         if (INTEL_INFO(dev)->gen >= 6) {
+                seq_printf(m, "  RC PSMI: 0x%08x\n", error->rc_psmi[ring]);
                 seq_printf(m, "  FAULT_REG: 0x%08x\n", error->fault_reg[ring]);
                 seq_printf(m, "  SYNC_0: 0x%08x\n",
                            error->semaphore_mboxes[ring][0]);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 476c64c4844c..627fe35781b4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -190,6 +190,7 @@ struct drm_i915_error_state {
         u32 instdone[I915_NUM_RINGS];
         u32 acthd[I915_NUM_RINGS];
         u32 semaphore_mboxes[I915_NUM_RINGS][I915_NUM_RINGS - 1];
+        u32 rc_psmi[I915_NUM_RINGS]; /* sleep state */
         /* our own tracking of ring head and tail */
         u32 cpu_ring_head[I915_NUM_RINGS];
         u32 cpu_ring_tail[I915_NUM_RINGS];
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 23f2ea0f0651..566f61b9e47c 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1067,6 +1067,7 @@ static void i915_record_ring_state(struct drm_device *dev,
         struct drm_i915_private *dev_priv = dev->dev_private;
 
         if (INTEL_INFO(dev)->gen >= 6) {
+                error->rc_psmi[ring->id] = I915_READ(ring->mmio_base + 0x50);
                 error->fault_reg[ring->id] = I915_READ(RING_FAULT_REG(ring));
                 error->semaphore_mboxes[ring->id][0]
                         = I915_READ(RING_SYNC_0(ring->mmio_base));
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index ac5688e8b01d..7aa6e97c2c72 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -690,10 +690,10 @@
 #define   GEN6_BLITTER_FBC_NOTIFY                       (1<<3)
 
 #define GEN6_BSD_SLEEP_PSMI_CONTROL     0x12050
-#define   GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_MODIFY_MASK       (1 << 16)
-#define   GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_DISABLE           (1 << 0)
-#define   GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_ENABLE            0
-#define   GEN6_BSD_SLEEP_PSMI_CONTROL_IDLE_INDICATOR                    (1 << 3)
+#define   GEN6_BSD_SLEEP_MSG_DISABLE    (1 << 0)
+#define   GEN6_BSD_SLEEP_FLUSH_DISABLE  (1 << 2)
+#define   GEN6_BSD_SLEEP_INDICATOR      (1 << 3)
+#define   GEN6_BSD_GO_INDICATOR         (1 << 4)
 
 #define GEN6_BSD_HWSTAM                 0x12098
 #define GEN6_BSD_IMR                    0x120a8
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index d42d821c64d6..ddc48590ea60 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1270,20 +1270,31 @@ static void gen6_bsd_ring_write_tail(struct intel_ring_buffer *ring,
         drm_i915_private_t *dev_priv = ring->dev->dev_private;
 
        /* Every tail move must follow the sequence below */
+
+        /* Disable notification that the ring is IDLE. The GT
+         * will then assume that it is busy and bring it out of rc6.
+         */
         I915_WRITE(GEN6_BSD_SLEEP_PSMI_CONTROL,
-                GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_MODIFY_MASK |
-                GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_DISABLE);
-        I915_WRITE(GEN6_BSD_RNCID, 0x0);
+                   _MASKED_BIT_ENABLE(GEN6_BSD_SLEEP_MSG_DISABLE));
+
+        /* Clear the context id. Here be magic! */
+        I915_WRITE64(GEN6_BSD_RNCID, 0x0);
 
+        /* Wait for the ring not to be idle, i.e. for it to wake up. */
         if (wait_for((I915_READ(GEN6_BSD_SLEEP_PSMI_CONTROL) &
-                GEN6_BSD_SLEEP_PSMI_CONTROL_IDLE_INDICATOR) == 0,
-                50))
-        DRM_ERROR("timed out waiting for IDLE Indicator\n");
+                      GEN6_BSD_SLEEP_INDICATOR) == 0,
+                     50))
+                DRM_ERROR("timed out waiting for the BSD ring to wake up\n");
 
+        /* Now that the ring is fully powered up, update the tail */
         I915_WRITE_TAIL(ring, value);
+        POSTING_READ(RING_TAIL(ring->mmio_base));
+
+        /* Let the ring send IDLE messages to the GT again,
+         * and so let it sleep to conserve power when idle.
+         */
         I915_WRITE(GEN6_BSD_SLEEP_PSMI_CONTROL,
-                GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_MODIFY_MASK |
-                GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_ENABLE);
+                   _MASKED_BIT_DISABLE(GEN6_BSD_SLEEP_MSG_DISABLE));
 }
 
 static int gen6_ring_flush(struct intel_ring_buffer *ring,