drm/i915: Change forcewake timeout to 2ms

A designer familiar with the hardware has stated that the forcewake
timeout can theoretically be as high as a little over 1ms. Therefore we
modify our code to use 2ms (appropriate fudge and because we don't want
to round down).

Hopefully this can't prevent spurious timeouts.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Acked-by: Chris Wilson <chris@chris-wilson.oc.uk>
[danvet: again fix conflict with vlv patch.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -31,7 +31,7 @@
 #include "../../../platform/x86/intel_ips.h"
 #include <linux/module.h>
 
-#define FORCEWAKE_ACK_TIMEOUT_US 500
+#define FORCEWAKE_ACK_TIMEOUT_MS 2
 
 /* FBC, or Frame Buffer Compression, is a technique employed to compress the
  * framebuffer contents in-memory, aiming at reducing the required bandwidth
@@ -3964,15 +3964,15 @@ static void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv)
 	else
 		forcewake_ack = FORCEWAKE_ACK;
 
-	if (wait_for_atomic_us((I915_READ_NOTRACE(forcewake_ack) & 1) == 0,
-			       FORCEWAKE_ACK_TIMEOUT_US))
+	if (wait_for_atomic((I915_READ_NOTRACE(forcewake_ack) & 1) == 0,
+			    FORCEWAKE_ACK_TIMEOUT_MS))
 		DRM_ERROR("Timed out waiting for forcewake old ack to clear.\n");
 
 	I915_WRITE_NOTRACE(FORCEWAKE, 1);
 	POSTING_READ(FORCEWAKE);
 
-	if (wait_for_atomic_us((I915_READ_NOTRACE(forcewake_ack) & 1),
-			       FORCEWAKE_ACK_TIMEOUT_US))
+	if (wait_for_atomic((I915_READ_NOTRACE(forcewake_ack) & 1),
+			    FORCEWAKE_ACK_TIMEOUT_MS))
 		DRM_ERROR("Timed out waiting for forcewake to ack request.\n");
 
 	__gen6_gt_wait_for_thread_c0(dev_priv);
@@ -3987,15 +3987,15 @@ static void __gen6_gt_force_wake_mt_get(struct drm_i915_private *dev_priv)
 	else
 		forcewake_ack = FORCEWAKE_MT_ACK;
 
-	if (wait_for_atomic_us((I915_READ_NOTRACE(forcewake_ack) & 1) == 0,
-			       FORCEWAKE_ACK_TIMEOUT_US))
+	if (wait_for_atomic((I915_READ_NOTRACE(forcewake_ack) & 1) == 0,
+			    FORCEWAKE_ACK_TIMEOUT_MS))
 		DRM_ERROR("Timed out waiting for forcewake old ack to clear.\n");
 
 	I915_WRITE_NOTRACE(FORCEWAKE_MT, _MASKED_BIT_ENABLE(1));
 	POSTING_READ(FORCEWAKE_MT);
 
-	if (wait_for_atomic_us((I915_READ_NOTRACE(forcewake_ack) & 1),
-			       FORCEWAKE_ACK_TIMEOUT_US))
+	if (wait_for_atomic((I915_READ_NOTRACE(forcewake_ack) & 1),
+			    FORCEWAKE_ACK_TIMEOUT_MS))
 		DRM_ERROR("Timed out waiting for forcewake to ack request.\n");
 
 	__gen6_gt_wait_for_thread_c0(dev_priv);
@@ -4075,14 +4075,14 @@ int __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
 
 static void vlv_force_wake_get(struct drm_i915_private *dev_priv)
 {
-	if (wait_for_atomic_us((I915_READ_NOTRACE(FORCEWAKE_ACK_VLV) & 1) == 0,
-			       FORCEWAKE_ACK_TIMEOUT_US))
+	if (wait_for_atomic((I915_READ_NOTRACE(FORCEWAKE_ACK_VLV) & 1) == 0,
+			    FORCEWAKE_ACK_TIMEOUT_MS))
 		DRM_ERROR("Timed out waiting for forcewake old ack to clear.\n");
 
 	I915_WRITE_NOTRACE(FORCEWAKE_VLV, _MASKED_BIT_ENABLE(1));
 
-	if (wait_for_atomic_us((I915_READ_NOTRACE(FORCEWAKE_ACK_VLV) & 1),
-			       FORCEWAKE_ACK_TIMEOUT_US))
+	if (wait_for_atomic((I915_READ_NOTRACE(FORCEWAKE_ACK_VLV) & 1),
+			    FORCEWAKE_ACK_TIMEOUT_MS))
 		DRM_ERROR("Timed out waiting for forcewake to ack request.\n");
 
 	__gen6_gt_wait_for_thread_c0(dev_priv);