drm/i915: Fix Sandybridge fence registers

With 5 places to update when adding handling for fence registers, it is
easy to overlook one or two. Correct that oversight, but fence
management should be improved before a new set of registers is added.

Bugzilla: https://bugs.freedesktop.org/show_bug?id=30199
Original patch by: Yuanhan Liu <yuanhan.liu@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

2 files changed, 51 insertions, 22 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 16fca1d1799..cf4ffbee1c0 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2351,14 +2351,21 @@ i915_gem_object_get_fence_reg(struct drm_gem_object *obj)
 
         reg->obj = obj;
 
-        if (IS_GEN6(dev))
+        switch (INTEL_INFO(dev)->gen) {
+        case 6:
                 sandybridge_write_fence_reg(reg);
-        else if (IS_I965G(dev))
+                break;
+        case 5:
+        case 4:
                 i965_write_fence_reg(reg);
-        else if (IS_I9XX(dev))
+                break;
+        case 3:
                 i915_write_fence_reg(reg);
-        else
+                break;
+        case 2:
                 i830_write_fence_reg(reg);
+                break;
+        }
 
         trace_i915_gem_object_get_fence(obj, obj_priv->fence_reg,
                         obj_priv->tiling_mode);
@@ -2381,22 +2388,26 @@ i915_gem_clear_fence_reg(struct drm_gem_object *obj)
         struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
         struct drm_i915_fence_reg *reg =
                 &dev_priv->fence_regs[obj_priv->fence_reg];
+        uint32_t fence_reg;
 
-        if (IS_GEN6(dev)) {
+        switch (INTEL_INFO(dev)->gen) {
+        case 6:
                 I915_WRITE64(FENCE_REG_SANDYBRIDGE_0 +
                              (obj_priv->fence_reg * 8), 0);
-        } else if (IS_I965G(dev)) {
+                break;
+        case 5:
+        case 4:
                 I915_WRITE64(FENCE_REG_965_0 + (obj_priv->fence_reg * 8), 0);
-        } else {
-                uint32_t fence_reg;
-
-                if (obj_priv->fence_reg < 8)
-                        fence_reg = FENCE_REG_830_0 + obj_priv->fence_reg * 4;
+                break;
+        case 3:
+                if (obj_priv->fence_reg > 8)
+                        fence_reg = FENCE_REG_945_8 + (obj_priv->fence_reg - 8) * 4;
                 else
-                        fence_reg = FENCE_REG_945_8 + (obj_priv->fence_reg -
-                                                       8) * 4;
+        case 2:
+                        fence_reg = FENCE_REG_830_0 + obj_priv->fence_reg * 4;
 
                 I915_WRITE(fence_reg, 0);
+                break;
         }
 
         reg->obj = NULL;
diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index 2c6b98f2440..31f08581e93 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -789,16 +789,25 @@ int i915_save_state(struct drm_device *dev)
                 dev_priv->saveSWF2[i] = I915_READ(SWF30 + (i << 2));
 
         /* Fences */
-        if (IS_I965G(dev)) {
+        switch (INTEL_INFO(dev)->gen) {
+        case 6:
+                for (i = 0; i < 16; i++)
+                        dev_priv->saveFENCE[i] = I915_READ64(FENCE_REG_SANDYBRIDGE_0 + (i * 8));
+                break;
+        case 5:
+        case 4:
                 for (i = 0; i < 16; i++)
                         dev_priv->saveFENCE[i] = I915_READ64(FENCE_REG_965_0 + (i * 8));
-        } else {
-                for (i = 0; i < 8; i++)
-                        dev_priv->saveFENCE[i] = I915_READ(FENCE_REG_830_0 + (i * 4));
-
+                break;
+        case 3:
                 if (IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
                         for (i = 0; i < 8; i++)
                                 dev_priv->saveFENCE[i+8] = I915_READ(FENCE_REG_945_8 + (i * 4));
+        case 2:
+                for (i = 0; i < 8; i++)
+                        dev_priv->saveFENCE[i] = I915_READ(FENCE_REG_830_0 + (i * 4));
+                break;
+
         }
 
         return 0;
@@ -815,15 +824,24 @@ int i915_restore_state(struct drm_device *dev)
         I915_WRITE(HWS_PGA, dev_priv->saveHWS);
 
         /* Fences */
-        if (IS_I965G(dev)) {
+        switch (INTEL_INFO(dev)->gen) {
+        case 6:
+                for (i = 0; i < 16; i++)
+                        I915_WRITE64(FENCE_REG_SANDYBRIDGE_0 + (i * 8), dev_priv->saveFENCE[i]);
+                break;
+        case 5:
+        case 4:
                 for (i = 0; i < 16; i++)
                         I915_WRITE64(FENCE_REG_965_0 + (i * 8), dev_priv->saveFENCE[i]);
-        } else {
-                for (i = 0; i < 8; i++)
-                        I915_WRITE(FENCE_REG_830_0 + (i * 4), dev_priv->saveFENCE[i]);
+                break;
+        case 3:
+        case 2:
                 if (IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
                         for (i = 0; i < 8; i++)
                                 I915_WRITE(FENCE_REG_945_8 + (i * 4), dev_priv->saveFENCE[i+8]);
+                for (i = 0; i < 8; i++)
+                        I915_WRITE(FENCE_REG_830_0 + (i * 4), dev_priv->saveFENCE[i]);
+                break;
         }
 
         i915_restore_display(dev);