[Intel-gfx] [PATCH 2/2] drm/i915: Fix GT wake FIFO free entries for VLV

[ville.syrjala at linux.intel.com]

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

On VLV the GTFIFOCTL register has other bits besides the number of free
entries in the GT wake FIFO. Apply a mask when we read th register to
make sure we don't misinterpret the number of free FIFO entries.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h     | 3 ++-
 drivers/gpu/drm/i915/intel_uncore.c | 6 +++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index e8f47de..e243105 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4860,7 +4860,8 @@
 #define    GT_FIFO_IAWRERR			(1<<1)
 #define    GT_FIFO_IARDERR			(1<<0)
 
-#define  GT_FIFO_FREE_ENTRIES			0x120008
+#define  GTFIFOCTL				0x120008
+#define    GT_FIFO_FREE_ENTRIES_MASK		0x7f
 #define    GT_FIFO_NUM_RESERVED_ENTRIES		20
 
 #define  HSW_IDICR				0x9008
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index a9849ab..71902c4 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -148,10 +148,10 @@ static int __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
 
 	if (dev_priv->uncore.fifo_count < GT_FIFO_NUM_RESERVED_ENTRIES) {
 		int loop = 500;
-		u32 fifo = __raw_i915_read32(dev_priv, GT_FIFO_FREE_ENTRIES);
+		u32 fifo = __raw_i915_read32(dev_priv, GTFIFOCTL) & GT_FIFO_FREE_ENTRIES_MASK;
 		while (fifo <= GT_FIFO_NUM_RESERVED_ENTRIES && loop--) {
 			udelay(10);
-			fifo = __raw_i915_read32(dev_priv, GT_FIFO_FREE_ENTRIES);
+			fifo = __raw_i915_read32(dev_priv, GTFIFOCTL) & GT_FIFO_FREE_ENTRIES_MASK;
 		}
 		if (WARN_ON(loop < 0 && fifo <= GT_FIFO_NUM_RESERVED_ENTRIES))
 			++ret;
@@ -806,7 +806,7 @@ static int gen6_do_reset(struct drm_device *dev)
 		dev_priv->uncore.funcs.force_wake_put(dev_priv);
 
 	/* Restore fifo count */
-	dev_priv->uncore.fifo_count = __raw_i915_read32(dev_priv, GT_FIFO_FREE_ENTRIES);
+	dev_priv->uncore.fifo_count = __raw_i915_read32(dev_priv, GTFIFOCTL) & GT_FIFO_FREE_ENTRIES_MASK;
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 	return ret;
-- 
1.8.1.5