[Intel-gfx] [PATCH] drm/i915: GMBUS don't need no forcewake

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

GMBUS is part of the display engine, and thus has no need for
forcewake. Let's not bother trying to grab it then.

I don't recall if the display engine suffers from system hangs
due to multiple accesses to the same "cacheline" in mmio space.
I hope not since we're no longer protected by the uncore lock
since commit 4e6c2d58ba86 ("drm/i915: Take forcewake once for
the entire GMBUS transaction")

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: David Weinehall <david.weinehall at linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_i2c.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index 79aab9ad6faa..49c7824a4c29 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -468,13 +468,9 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num)
 					       struct intel_gmbus,
 					       adapter);
 	struct drm_i915_private *dev_priv = bus->dev_priv;
-	const unsigned int fw =
-		intel_uncore_forcewake_for_reg(dev_priv, GMBUS0,
-					       FW_REG_READ | FW_REG_WRITE);
 	int i = 0, inc, try = 0;
 	int ret = 0;
 
-	intel_uncore_forcewake_get(dev_priv, fw);
 retry:
 	I915_WRITE_FW(GMBUS0, bus->reg0);
 
@@ -576,7 +572,6 @@ timeout:
 	ret = -EAGAIN;
 
 out:
-	intel_uncore_forcewake_put(dev_priv, fw);
 	return ret;
 }
 
-- 
2.7.4