drm/i915: Fix GT wake FIFO free entries for VLV

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@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[danvet: There's some unclarity about hsw, but brushed off as todays'
Bspec just acting up a bit.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 4f84573..2658d97 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4865,7 +4865,8 @@
 #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 cff6610..97ae8bd 100644 (file)
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -152,10 +152,10 @@ 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;
@@ -942,7 +942,7 @@ static int gen6_do_reset(struct drm_device *dev)
                dev_priv->uncore.funcs.force_wake_put(dev_priv, FORCEWAKE_ALL);
 
        /* 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;