drm/i915: don't rewrite the GTT on resume v4
The BIOS shouldn't be touching this memory across suspend/resume, so
just leave it alone. This saves us ~6ms on resume on my T420 (retested
with write combined PTEs).
v2: change gtt restore default on pre-gen4 (Chris)
move needs_gtt_restore flag into dev_priv
v3: make sure we restore GTT on resume from hibernate (Daniel)
use opregion support as the cutoff for restore from resume (Chris)
v4: use a better check for opregion (Chris)
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Kill the needs_gtt_restore indirection and check directly for
OpRegion. Also explain in a comment what's going on.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 577858b..f8ba5fe 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -537,19 +537,11 @@
console_unlock();
}
-static int i915_drm_thaw(struct drm_device *dev)
+static int __i915_drm_thaw(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
int error = 0;
- intel_gt_reset(dev);
-
- if (drm_core_check_feature(dev, DRIVER_MODESET)) {
- mutex_lock(&dev->struct_mutex);
- i915_gem_restore_gtt_mappings(dev);
- mutex_unlock(&dev->struct_mutex);
- }
-
i915_restore_state(dev);
intel_opregion_setup(dev);
@@ -588,8 +580,26 @@
return error;
}
+static int i915_drm_thaw(struct drm_device *dev)
+{
+ int error = 0;
+
+ intel_gt_reset(dev);
+
+ if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+ mutex_lock(&dev->struct_mutex);
+ i915_gem_restore_gtt_mappings(dev);
+ mutex_unlock(&dev->struct_mutex);
+ }
+
+ __i915_drm_thaw(dev);
+
+ return error;
+}
+
int i915_resume(struct drm_device *dev)
{
+ struct drm_i915_private *dev_priv = dev->dev_private;
int ret;
if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
@@ -600,7 +610,20 @@
pci_set_master(dev->pdev);
- ret = i915_drm_thaw(dev);
+ intel_gt_reset(dev);
+
+ /*
+ * Platforms with opregion should have sane BIOS, older ones (gen3 and
+ * earlier) need this since the BIOS might clear all our scratch PTEs.
+ */
+ if (drm_core_check_feature(dev, DRIVER_MODESET) &&
+ !dev_priv->opregion.header) {
+ mutex_lock(&dev->struct_mutex);
+ i915_gem_restore_gtt_mappings(dev);
+ mutex_unlock(&dev->struct_mutex);
+ }
+
+ ret = __i915_drm_thaw(dev);
if (ret)
return ret;