[PATCH 17/68] Revert "drm/i915/bdw: Use timeout mode for RC6 on bdw"

[Ben Widawsky <benjamin.widawsky@intel.com>]

This reverts commit 0d68b25e9ceb344fe2f93373b1c0311d33814265.

At one time I bisected reset breakage to this patch by using a mesa that is
guaranteed to generate a hang when using the fs, and then running the following
test case:

./bin/shader_runner  tests/shaders/glsl-algebraic-add-zero.shader_test -auto
./bin/shader_runner  tests/shaders/glsl-fs-texture2d.shader_test -auto
./bin/shader_runner  tests/shaders/glsl-algebraic-add-zero.shader_test -auto

The symptom is that after the first GPU hang, all subsequent commands
will hang the GPU.

Oddly at some point I believe this revert stopped fixing the issue, but I am
leaving it in the series to minimize variables.

---
 drivers/gpu/drm/i915/intel_pm.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 41de760..3255c10 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3658,23 +3658,15 @@ static void gen8_enable_rps(struct drm_device *dev)
 	for_each_ring(ring, dev_priv, unused)
 		I915_WRITE(RING_MAX_IDLE(ring->mmio_base), 10);
 	I915_WRITE(GEN6_RC_SLEEP, 0);
-	if (IS_BROADWELL(dev))
-		I915_WRITE(GEN6_RC6_THRESHOLD, 625); /* 800us/1.28 for TO */
-	else
-		I915_WRITE(GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
+	I915_WRITE(GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
 
 	/* 3: Enable RC6 */
 	if (intel_enable_rc6(dev) & INTEL_RC6_ENABLE)
 		rc6_mask = GEN6_RC_CTL_RC6_ENABLE;
 	intel_print_rc6_info(dev, rc6_mask);
-	if (IS_BROADWELL(dev))
-		I915_WRITE(GEN6_RC_CONTROL, GEN6_RC_CTL_HW_ENABLE |
-				GEN7_RC_CTL_TO_MODE |
-				rc6_mask);
-	else
-		I915_WRITE(GEN6_RC_CONTROL, GEN6_RC_CTL_HW_ENABLE |
-				GEN6_RC_CTL_EI_MODE(1) |
-				rc6_mask);
+	I915_WRITE(GEN6_RC_CONTROL, GEN6_RC_CTL_HW_ENABLE |
+				    GEN6_RC_CTL_EI_MODE(1) |
+				    rc6_mask);
 
 	/* 4 Program defaults and thresholds for RPS*/
 	I915_WRITE(GEN6_RPNSWREQ,
-- 
2.0.4