[Intel-gfx] [PATCH 01/14] drm/i915: Nuke posting reads from plane update/disable funcs

[Ville Syrjala]

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

No need for the posting reads in the plane update/disable hooks.
If we need a posting read for something then a single one at the
very end would be sufficient. We have that anyway in the form
of eg. scanline/frame counter reads.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |  6 ------
 drivers/gpu/drm/i915/intel_sprite.c  | 12 ------------
 2 files changed, 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 7e1131d806ae..c5ce3892d583 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3378,7 +3378,6 @@ static void i9xx_update_plane(struct intel_plane *plane,
 			      intel_plane_ggtt_offset(plane_state) +
 			      dspaddr_offset);
 	}
-	POSTING_READ_FW(reg);
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
@@ -3397,7 +3396,6 @@ static void i9xx_disable_plane(struct intel_plane *plane,
 		I915_WRITE_FW(DSPSURF(i9xx_plane), 0);
 	else
 		I915_WRITE_FW(DSPADDR(i9xx_plane), 0);
-	POSTING_READ_FW(DSPCNTR(i9xx_plane));
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
@@ -9850,8 +9848,6 @@ static void i845_update_cursor(struct intel_plane *plane,
 		I915_WRITE_FW(CURPOS(PIPE_A), pos);
 	}
 
-	POSTING_READ_FW(CURCNTR(PIPE_A));
-
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
@@ -10080,8 +10076,6 @@ static void i9xx_update_cursor(struct intel_plane *plane,
 		I915_WRITE_FW(CURBASE(pipe), base);
 	}
 
-	POSTING_READ_FW(CURBASE(pipe));
-
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 20b5b9ff782f..bd7d988d7512 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -463,7 +463,6 @@ skl_program_plane(struct intel_plane *plane,
 	I915_WRITE_FW(PLANE_CTL(pipe, plane_id), plane_ctl);
 	I915_WRITE_FW(PLANE_SURF(pipe, plane_id),
 		      intel_plane_ggtt_offset(plane_state) + surf_addr);
-	POSTING_READ_FW(PLANE_SURF(pipe, plane_id));
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
@@ -504,9 +503,7 @@ skl_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc)
 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
 
 	I915_WRITE_FW(PLANE_CTL(pipe, plane_id), 0);
-
 	I915_WRITE_FW(PLANE_SURF(pipe, plane_id), 0);
-	POSTING_READ_FW(PLANE_SURF(pipe, plane_id));
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
@@ -752,7 +749,6 @@ vlv_update_plane(struct intel_plane *plane,
 	I915_WRITE_FW(SPCNTR(pipe, plane_id), sprctl);
 	I915_WRITE_FW(SPSURF(pipe, plane_id),
 		      intel_plane_ggtt_offset(plane_state) + sprsurf_offset);
-	POSTING_READ_FW(SPSURF(pipe, plane_id));
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
@@ -768,9 +764,7 @@ vlv_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc)
 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
 
 	I915_WRITE_FW(SPCNTR(pipe, plane_id), 0);
-
 	I915_WRITE_FW(SPSURF(pipe, plane_id), 0);
-	POSTING_READ_FW(SPSURF(pipe, plane_id));
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
@@ -918,7 +912,6 @@ ivb_update_plane(struct intel_plane *plane,
 	I915_WRITE_FW(SPRCTL(pipe), sprctl);
 	I915_WRITE_FW(SPRSURF(pipe),
 		      intel_plane_ggtt_offset(plane_state) + sprsurf_offset);
-	POSTING_READ_FW(SPRSURF(pipe));
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
@@ -936,9 +929,7 @@ ivb_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc)
 	/* Can't leave the scaler enabled... */
 	if (IS_IVYBRIDGE(dev_priv))
 		I915_WRITE_FW(SPRSCALE(pipe), 0);
-
 	I915_WRITE_FW(SPRSURF(pipe), 0);
-	POSTING_READ_FW(SPRSURF(pipe));
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
@@ -1085,7 +1076,6 @@ g4x_update_plane(struct intel_plane *plane,
 	I915_WRITE_FW(DVSCNTR(pipe), dvscntr);
 	I915_WRITE_FW(DVSSURF(pipe),
 		      intel_plane_ggtt_offset(plane_state) + dvssurf_offset);
-	POSTING_READ_FW(DVSSURF(pipe));
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
@@ -1102,9 +1092,7 @@ g4x_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc)
 	I915_WRITE_FW(DVSCNTR(pipe), 0);
 	/* Disable the scaler */
 	I915_WRITE_FW(DVSSCALE(pipe), 0);
-
 	I915_WRITE_FW(DVSSURF(pipe), 0);
-	POSTING_READ_FW(DVSSURF(pipe));
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
-- 
2.18.1