drm/i915: add dynamic clock frequency control
There are several sources of unnecessary power consumption on Intel
graphics systems. The first is the LVDS clock. TFTs don't suffer from
persistence issues like CRTs, and so we can reduce the LVDS refresh rate
when the screen is idle. It will be automatically upclocked when
userspace triggers graphical activity. Beyond that, we can enable memory
self refresh. This allows the memory to go into a lower power state when
the graphics are idle. Finally, we can drop some clocks on the gpu
itself. All of these things can be reenabled between frames when GPU
activity is triggered, and so there should be no user visible graphical
changes.
Signed-off-by: Jesse Barnes <jesse.barnes@intel.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
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 7edb5b9..73b5819 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -29,6 +29,7 @@
#include "drm.h"
#include "i915_drm.h"
#include "i915_drv.h"
+#include "intel_drv.h"
#include <linux/swap.h>
#include <linux/pci.h>
@@ -981,6 +982,7 @@
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_set_domain *args = data;
struct drm_gem_object *obj;
+ struct drm_i915_gem_object *obj_priv;
uint32_t read_domains = args->read_domains;
uint32_t write_domain = args->write_domain;
int ret;
@@ -1004,15 +1006,17 @@
obj = drm_gem_object_lookup(dev, file_priv, args->handle);
if (obj == NULL)
return -EBADF;
+ obj_priv = obj->driver_private;
mutex_lock(&dev->struct_mutex);
+
+ intel_mark_busy(dev, obj);
+
#if WATCH_BUF
DRM_INFO("set_domain_ioctl %p(%zd), %08x %08x\n",
obj, obj->size, read_domains, write_domain);
#endif
if (read_domains & I915_GEM_DOMAIN_GTT) {
- struct drm_i915_gem_object *obj_priv = obj->driver_private;
-
ret = i915_gem_object_set_to_gtt_domain(obj, write_domain != 0);
/* Update the LRU on the fence for the CPU access that's
@@ -2776,6 +2780,8 @@
BUG_ON(obj->pending_read_domains & I915_GEM_DOMAIN_CPU);
BUG_ON(obj->pending_write_domain == I915_GEM_DOMAIN_CPU);
+ intel_mark_busy(dev, obj);
+
#if WATCH_BUF
DRM_INFO("%s: object %p read %08x -> %08x write %08x -> %08x\n",
__func__, obj,