drm/i915: add media well to VLV force wake routines v2

We could split this out into a separate routine at some point as an
optimization.

v2: use FORCEWAKE_KERNEL (Ville)

Note: Ville mentioned in his review that he declines to be responsible
if this blows up due to the lack of "readback a register != FW_ACK,
but from the same cacheline" magic we have in other forcewake
implementations.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[danvet: Bikeshed overtly long lines according to checkpatch.pl. Nope,
this time around I didn't screw up printk message since I've left
those alone.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 13 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 176cf5c58507..17cb78f5760a 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4148,6 +4148,8 @@
 #define  FORCEWAKE                              0xA18C
 #define  FORCEWAKE_VLV                          0x1300b0
 #define  FORCEWAKE_ACK_VLV                      0x1300b4
+#define  FORCEWAKE_MEDIA_VLV                    0x1300b8
+#define  FORCEWAKE_ACK_MEDIA_VLV                0x1300bc
 #define  FORCEWAKE_ACK_HSW                      0x130044
 #define  FORCEWAKE_ACK                          0x130090
 #define  VLV_GTLC_WAKE_CTRL                     0x130090
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index c30e89a45236..52d4f2d660db 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4404,10 +4404,17 @@ static void vlv_force_wake_get(struct drm_i915_private *dev_priv)
                 DRM_ERROR("Timed out waiting for forcewake old ack to clear.\n");
 
         I915_WRITE_NOTRACE(FORCEWAKE_VLV, _MASKED_BIT_ENABLE(FORCEWAKE_KERNEL));
+        I915_WRITE_NOTRACE(FORCEWAKE_MEDIA_VLV,
+                           _MASKED_BIT_ENABLE(FORCEWAKE_KERNEL));
 
         if (wait_for_atomic((I915_READ_NOTRACE(FORCEWAKE_ACK_VLV) & FORCEWAKE_KERNEL),
                             FORCEWAKE_ACK_TIMEOUT_MS))
-                DRM_ERROR("Timed out waiting for forcewake to ack request.\n");
+                DRM_ERROR("Timed out waiting for GT to ack forcewake request.\n");
+
+        if (wait_for_atomic((I915_READ_NOTRACE(FORCEWAKE_ACK_MEDIA_VLV) &
+                             FORCEWAKE_KERNEL),
+                            FORCEWAKE_ACK_TIMEOUT_MS))
+                DRM_ERROR("Timed out waiting for media to ack forcewake request.\n");
 
         __gen6_gt_wait_for_thread_c0(dev_priv);
 }
@@ -4415,8 +4422,9 @@ static void vlv_force_wake_get(struct drm_i915_private *dev_priv)
 static void vlv_force_wake_put(struct drm_i915_private *dev_priv)
 {
         I915_WRITE_NOTRACE(FORCEWAKE_VLV, _MASKED_BIT_DISABLE(FORCEWAKE_KERNEL));
-        /* something from same cacheline, but !FORCEWAKE_VLV */
-        POSTING_READ(FORCEWAKE_ACK_VLV);
+        I915_WRITE_NOTRACE(FORCEWAKE_MEDIA_VLV,
+                           _MASKED_BIT_DISABLE(FORCEWAKE_KERNEL));
+        /* The below doubles as a POSTING_READ */
         gen6_gt_check_fifodbg(dev_priv);
 }