[Intel-gfx] [PATCH 10/18] drm/i915/hsw, bdw: Remove redundant state check during power well toggling

[Imre Deak]

Similarly to the GEN9 power well toggling, saving an occasional extra
MMIO write is not worth the code complexity, let's simplify things.

Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/intel_runtime_pm.c | 36 ++++++++++++---------------------
 1 file changed, 13 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 28d2ea9..00e97ee 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -399,36 +399,26 @@ static void gen9_wait_for_power_well_disable(struct drm_i915_private *dev_priv,
 static void hsw_set_power_well(struct drm_i915_private *dev_priv,
 			       struct i915_power_well *power_well, bool enable)
 {
-	bool is_enabled, enable_requested;
 	uint32_t tmp;
 
 	tmp = I915_READ(HSW_PWR_WELL_DRIVER);
-	is_enabled = tmp & HSW_PWR_WELL_STATE_ENABLED;
-	enable_requested = tmp & HSW_PWR_WELL_ENABLE_REQUEST;
 
 	if (enable) {
-		if (!enable_requested)
-			I915_WRITE(HSW_PWR_WELL_DRIVER,
-				   HSW_PWR_WELL_ENABLE_REQUEST);
-
-		if (!is_enabled) {
-			DRM_DEBUG_KMS("Enabling power well\n");
-			if (intel_wait_for_register(dev_priv,
-						    HSW_PWR_WELL_DRIVER,
-						    HSW_PWR_WELL_STATE_ENABLED,
-						    HSW_PWR_WELL_STATE_ENABLED,
-						    20))
-				DRM_ERROR("Timeout enabling power well\n");
-			hsw_power_well_post_enable(dev_priv);
-		}
+		I915_WRITE(HSW_PWR_WELL_DRIVER, HSW_PWR_WELL_ENABLE_REQUEST);
 
+		DRM_DEBUG_KMS("Enabling power well\n");
+		if (intel_wait_for_register(dev_priv,
+					    HSW_PWR_WELL_DRIVER,
+					    HSW_PWR_WELL_STATE_ENABLED,
+					    HSW_PWR_WELL_STATE_ENABLED,
+					    20))
+			DRM_ERROR("Timeout enabling power well\n");
+		hsw_power_well_post_enable(dev_priv);
 	} else {
-		if (enable_requested) {
-			hsw_power_well_pre_disable(dev_priv);
-			I915_WRITE(HSW_PWR_WELL_DRIVER, 0);
-			POSTING_READ(HSW_PWR_WELL_DRIVER);
-			DRM_DEBUG_KMS("Requesting to disable the power well\n");
-		}
+		hsw_power_well_pre_disable(dev_priv);
+		I915_WRITE(HSW_PWR_WELL_DRIVER, 0);
+		POSTING_READ(HSW_PWR_WELL_DRIVER);
+		DRM_DEBUG_KMS("Requesting to disable the power well\n");
 	}
 }
 
-- 
2.7.4