drm/i915: fix 945 fence register writes for fence 8 and above.
The last 8 fence registers sit at a different offset, so when we went to set
fence number 8 in the lower offset, we instead set PGETBL_CTL, and the GPU
got all sorts of angry at us.
fd.o bug #20567. Easily reproducible by running glxgears and killing it about
6 times.
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b0ff5c4..37427e4 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1476,7 +1476,7 @@
struct drm_i915_gem_object *obj_priv = obj->driver_private;
int regnum = obj_priv->fence_reg;
int tile_width;
- uint32_t val;
+ uint32_t fence_reg, val;
uint32_t pitch_val;
if ((obj_priv->gtt_offset & ~I915_FENCE_START_MASK) ||
@@ -1503,7 +1503,11 @@
val |= pitch_val << I830_FENCE_PITCH_SHIFT;
val |= I830_FENCE_REG_VALID;
- I915_WRITE(FENCE_REG_830_0 + (regnum * 4), val);
+ if (regnum < 8)
+ fence_reg = FENCE_REG_830_0 + (regnum * 4);
+ else
+ fence_reg = FENCE_REG_945_8 + ((regnum - 8) * 4);
+ I915_WRITE(fence_reg, val);
}
static void i830_write_fence_reg(struct drm_i915_fence_reg *reg)
@@ -1687,8 +1691,17 @@
if (IS_I965G(dev))
I915_WRITE64(FENCE_REG_965_0 + (obj_priv->fence_reg * 8), 0);
- else
- I915_WRITE(FENCE_REG_830_0 + (obj_priv->fence_reg * 4), 0);
+ else {
+ uint32_t fence_reg;
+
+ if (obj_priv->fence_reg < 8)
+ fence_reg = FENCE_REG_830_0 + obj_priv->fence_reg * 4;
+ else
+ fence_reg = FENCE_REG_945_8 + (obj_priv->fence_reg -
+ 8) * 4;
+
+ I915_WRITE(fence_reg, 0);
+ }
dev_priv->fence_regs[obj_priv->fence_reg].obj = NULL;
obj_priv->fence_reg = I915_FENCE_REG_NONE;