diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 8851315..60ea984 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -2004,8 +2004,11 @@ static int acpi_video_bus_put_one_device(struct acpi_video_device *device)
 	status = acpi_remove_notify_handler(device->dev->handle,
 					    ACPI_DEVICE_NOTIFY,
 					    acpi_video_device_notify);
-	sysfs_remove_link(&device->backlight->dev.kobj, "device");
-	backlight_device_unregister(device->backlight);
+	if (device->backlight) {
+		sysfs_remove_link(&device->backlight->dev.kobj, "device");
+		backlight_device_unregister(device->backlight);
+		device->backlight = NULL;
+	}
 	if (device->cdev) {
 		sysfs_remove_link(&device->dev->dev.kobj,
 				  "thermal_cooling");
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index fc4b68a..910bf75 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -43,6 +43,9 @@ module_param_named(modeset, i915_modeset, int, 0400);
 unsigned int i915_fbpercrtc = 0;
 module_param_named(fbpercrtc, i915_fbpercrtc, int, 0400);
 
+unsigned int i915_powersave = 0;
+module_param_named(powersave, i915_powersave, int, 0400);
+
 static struct drm_driver driver;
 
 static struct pci_device_id pciidlist[] = {
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b05b44d..8ca78e5 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -437,6 +437,11 @@ typedef struct drm_i915_private {
 		struct drm_i915_gem_phys_object *phys_objs[I915_MAX_PHYS_OBJECT];
 	} mm;
 	struct sdvo_device_mapping sdvo_mappings[2];
+
+	/* Reclocking support */
+	struct work_struct idle_work;
+	struct timer_list idle_timer;
+	bool busy;
 } drm_i915_private_t;
 
 /** driver private structure attached to each drm_gem_object */
@@ -566,6 +571,7 @@ enum intel_chip_family {
 extern struct drm_ioctl_desc i915_ioctls[];
 extern int i915_max_ioctl;
 extern unsigned int i915_fbpercrtc;
+extern unsigned int i915_powersave;
 
 extern int i915_master_create(struct drm_device *dev, struct drm_master *master);
 extern void i915_master_destroy(struct drm_device *dev, struct drm_master *master);
@@ -893,6 +899,9 @@ extern int i915_wait_ring(struct drm_device * dev, int n, const char *caller);
 /* dsparb controlled by hw only */
 #define DSPARB_HWCONTROL(dev) (IS_G4X(dev) || IS_IGDNG(dev))
 
+#define HAS_FW_BLC(dev) (IS_I9XX(dev) || IS_G4X(dev) || IS_IGDNG(dev))
+#define HAS_PIPE_CXSR(dev) (IS_G4X(dev) || IS_IGDNG(dev))
+
 #define PRIMARY_RINGBUFFER_SIZE         (128*1024)
 
 #endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 5bf4203..ce2d9b8 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>
 
@@ -980,6 +981,7 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
 {
 	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;
@@ -1003,8 +1005,12 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
 	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);
@@ -2761,6 +2767,8 @@ i915_gem_object_set_to_gpu_domain(struct drm_gem_object *obj)
 	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,
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 897a116..0c4b8f9 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -55,7 +55,7 @@
 /* PCI config space */
 
 #define HPLLCC	0xc0 /* 855 only */
-#define   GC_CLOCK_CONTROL_MASK		(3 << 0)
+#define   GC_CLOCK_CONTROL_MASK		(0xf << 0)
 #define   GC_CLOCK_133_200		(0 << 0)
 #define   GC_CLOCK_100_200		(1 << 0)
 #define   GC_CLOCK_100_133		(2 << 0)
@@ -1569,6 +1569,7 @@
 #define   PIPECONF_PROGRESSIVE	(0 << 21)
 #define   PIPECONF_INTERLACE_W_FIELD_INDICATION	(6 << 21)
 #define   PIPECONF_INTERLACE_FIELD_0_ONLY		(7 << 21)
+#define   PIPECONF_CXSR_DOWNCLOCK	(1<<16)
 #define PIPEASTAT		0x70024
 #define   PIPE_FIFO_UNDERRUN_STATUS		(1UL<<31)
 #define   PIPE_CRC_ERROR_ENABLE			(1UL<<29)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a58bfad..81f7687 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -36,6 +36,7 @@
 
 bool intel_pipe_has_type (struct drm_crtc *crtc, int type);
 static void intel_update_watermarks(struct drm_device *dev);
+static void intel_increase_displayclock(struct drm_crtc *crtc);
 
 typedef struct {
     /* given values */
@@ -65,6 +66,8 @@ struct intel_limit {
     intel_p2_t	    p2;
     bool (* find_pll)(const intel_limit_t *, struct drm_crtc *,
 		      int, int, intel_clock_t *);
+    bool (* find_reduced_pll)(const intel_limit_t *, struct drm_crtc *,
+			      int, int, intel_clock_t *);
 };
 
 #define I8XX_DOT_MIN		  25000
@@ -190,7 +193,7 @@ struct intel_limit {
 #define G4X_P2_SINGLE_CHANNEL_LVDS_LIMIT          0
 
 /*The parameter is for DUAL_CHANNEL_LVDS on G4x platform*/
-#define G4X_DOT_DUAL_CHANNEL_LVDS_MIN           80000
+#define G4X_DOT_DUAL_CHANNEL_LVDS_MIN           10000
 #define G4X_DOT_DUAL_CHANNEL_LVDS_MAX           224000
 #define G4X_N_DUAL_CHANNEL_LVDS_MIN             1
 #define G4X_N_DUAL_CHANNEL_LVDS_MAX             3
@@ -259,6 +262,9 @@ static bool
 intel_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 		    int target, int refclk, intel_clock_t *best_clock);
 static bool
+intel_find_best_reduced_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
+			    int target, int refclk, intel_clock_t *best_clock);
+static bool
 intel_g4x_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 			int target, int refclk, intel_clock_t *best_clock);
 static bool
@@ -281,6 +287,7 @@ static const intel_limit_t intel_limits_i8xx_dvo = {
 	.p2  = { .dot_limit = I8XX_P2_SLOW_LIMIT,
 		 .p2_slow = I8XX_P2_SLOW,	.p2_fast = I8XX_P2_FAST },
 	.find_pll = intel_find_best_PLL,
+	.find_reduced_pll = intel_find_best_reduced_PLL,
 };
 
 static const intel_limit_t intel_limits_i8xx_lvds = {
@@ -295,6 +302,7 @@ static const intel_limit_t intel_limits_i8xx_lvds = {
 	.p2  = { .dot_limit = I8XX_P2_SLOW_LIMIT,
 		 .p2_slow = I8XX_P2_LVDS_SLOW,	.p2_fast = I8XX_P2_LVDS_FAST },
 	.find_pll = intel_find_best_PLL,
+	.find_reduced_pll = intel_find_best_reduced_PLL,
 };
 	
 static const intel_limit_t intel_limits_i9xx_sdvo = {
@@ -309,6 +317,7 @@ static const intel_limit_t intel_limits_i9xx_sdvo = {
 	.p2  = { .dot_limit = I9XX_P2_SDVO_DAC_SLOW_LIMIT,
 		 .p2_slow = I9XX_P2_SDVO_DAC_SLOW,	.p2_fast = I9XX_P2_SDVO_DAC_FAST },
 	.find_pll = intel_find_best_PLL,
+	.find_reduced_pll = intel_find_best_reduced_PLL,
 };
 
 static const intel_limit_t intel_limits_i9xx_lvds = {
@@ -326,6 +335,7 @@ static const intel_limit_t intel_limits_i9xx_lvds = {
 	.p2  = { .dot_limit = I9XX_P2_LVDS_SLOW_LIMIT,
 		 .p2_slow = I9XX_P2_LVDS_SLOW,	.p2_fast = I9XX_P2_LVDS_FAST },
 	.find_pll = intel_find_best_PLL,
+	.find_reduced_pll = intel_find_best_reduced_PLL,
 };
 
     /* below parameter and function is for G4X Chipset Family*/
@@ -343,6 +353,7 @@ static const intel_limit_t intel_limits_g4x_sdvo = {
 		 .p2_fast = G4X_P2_SDVO_FAST
 	},
 	.find_pll = intel_g4x_find_best_PLL,
+	.find_reduced_pll = intel_g4x_find_best_PLL,
 };
 
 static const intel_limit_t intel_limits_g4x_hdmi = {
@@ -359,6 +370,7 @@ static const intel_limit_t intel_limits_g4x_hdmi = {
 		 .p2_fast = G4X_P2_HDMI_DAC_FAST
 	},
 	.find_pll = intel_g4x_find_best_PLL,
+	.find_reduced_pll = intel_g4x_find_best_PLL,
 };
 
 static const intel_limit_t intel_limits_g4x_single_channel_lvds = {
@@ -383,6 +395,7 @@ static const intel_limit_t intel_limits_g4x_single_channel_lvds = {
 		 .p2_fast = G4X_P2_SINGLE_CHANNEL_LVDS_FAST
 	},
 	.find_pll = intel_g4x_find_best_PLL,
+	.find_reduced_pll = intel_g4x_find_best_PLL,
 };
 
 static const intel_limit_t intel_limits_g4x_dual_channel_lvds = {
@@ -407,6 +420,7 @@ static const intel_limit_t intel_limits_g4x_dual_channel_lvds = {
 		 .p2_fast = G4X_P2_DUAL_CHANNEL_LVDS_FAST
 	},
 	.find_pll = intel_g4x_find_best_PLL,
+	.find_reduced_pll = intel_g4x_find_best_PLL,
 };
 
 static const intel_limit_t intel_limits_g4x_display_port = {
@@ -444,6 +458,7 @@ static const intel_limit_t intel_limits_igd_sdvo = {
 	.p2  = { .dot_limit = I9XX_P2_SDVO_DAC_SLOW_LIMIT,
 		 .p2_slow = I9XX_P2_SDVO_DAC_SLOW,	.p2_fast = I9XX_P2_SDVO_DAC_FAST },
 	.find_pll = intel_find_best_PLL,
+	.find_reduced_pll = intel_find_best_reduced_PLL,
 };
 
 static const intel_limit_t intel_limits_igd_lvds = {
@@ -459,6 +474,7 @@ static const intel_limit_t intel_limits_igd_lvds = {
 	.p2  = { .dot_limit = I9XX_P2_LVDS_SLOW_LIMIT,
 		 .p2_slow = I9XX_P2_LVDS_SLOW,	.p2_fast = I9XX_P2_LVDS_SLOW },
 	.find_pll = intel_find_best_PLL,
+	.find_reduced_pll = intel_find_best_reduced_PLL,
 };
 
 static const intel_limit_t intel_limits_igdng_sdvo = {
@@ -666,15 +682,16 @@ intel_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 
 	memset (best_clock, 0, sizeof (*best_clock));
 
-	for (clock.m1 = limit->m1.min; clock.m1 <= limit->m1.max; clock.m1++) {
-		for (clock.m2 = limit->m2.min; clock.m2 <= limit->m2.max; clock.m2++) {
-			/* m1 is always 0 in IGD */
-			if (clock.m2 >= clock.m1 && !IS_IGD(dev))
-				break;
-			for (clock.n = limit->n.min; clock.n <= limit->n.max;
-			     clock.n++) {
-				for (clock.p1 = limit->p1.min;
-				     clock.p1 <= limit->p1.max; clock.p1++) {
+	for (clock.p1 = limit->p1.max; clock.p1 >= limit->p1.min; clock.p1--) {
+		for (clock.m1 = limit->m1.min; clock.m1 <= limit->m1.max;
+		     clock.m1++) {
+			for (clock.m2 = limit->m2.min;
+			     clock.m2 <= limit->m2.max; clock.m2++) {
+				/* m1 is always 0 in IGD */
+				if (clock.m2 >= clock.m1 && !IS_IGD(dev))
+					break;
+				for (clock.n = limit->n.min;
+				     clock.n <= limit->n.max; clock.n++) {
 					int this_err;
 
 					intel_clock(dev, refclk, &clock);
@@ -695,6 +712,46 @@ intel_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 	return (err != target);
 }
 
+
+static bool
+intel_find_best_reduced_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
+			    int target, int refclk, intel_clock_t *best_clock)
+
+{
+	struct drm_device *dev = crtc->dev;
+	intel_clock_t clock;
+	int err = target;
+	bool found = false;
+
+	memcpy(&clock, best_clock, sizeof(intel_clock_t));
+
+	for (clock.m1 = limit->m1.min; clock.m1 <= limit->m1.max; clock.m1++) {
+		for (clock.m2 = limit->m2.min; clock.m2 <= limit->m2.max; clock.m2++) {
+			/* m1 is always 0 in IGD */
+			if (clock.m2 >= clock.m1 && !IS_IGD(dev))
+				break;
+			for (clock.n = limit->n.min; clock.n <= limit->n.max;
+			     clock.n++) {
+				int this_err;
+
+				intel_clock(dev, refclk, &clock);
+
+//				if (!intel_PLL_is_valid(crtc, &clock))
+//					continue;
+
+				this_err = abs(clock.dot - target);
+				if (this_err < err) {
+					*best_clock = clock;
+					err = this_err;
+					found = true;
+				}
+			}
+		}
+	}
+
+	return found;
+}
+
 static bool
 intel_g4x_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 			int target, int refclk, intel_clock_t *best_clock)
@@ -725,7 +782,7 @@ intel_g4x_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 	max_n = limit->n.max;
 	/* based on hardware requriment prefer smaller n to precision */
 	for (clock.n = limit->n.min; clock.n <= max_n; clock.n++) {
-		/* based on hardware requirment prefere larger m1,m2, p1 */
+		/* based on hardware requirment prefere larger m1,m2, */
 		for (clock.m1 = limit->m1.max;
 		     clock.m1 >= limit->m1.min; clock.m1--) {
 			for (clock.m2 = limit->m2.max;
@@ -735,8 +792,8 @@ intel_g4x_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 					int this_err;
 
 					intel_clock(dev, refclk, &clock);
-					if (!intel_PLL_is_valid(crtc, &clock))
-						continue;
+//					if (!intel_PLL_is_valid(crtc, &clock))
+//						continue;
 					this_err = abs(clock.dot - target) ;
 					if (this_err < err_most) {
 						*best_clock = clock;
@@ -778,15 +835,14 @@ intel_igdng_find_best_PLL(const intel_limit_t *limit, struct drm_crtc *crtc,
 
 	memset(best_clock, 0, sizeof(*best_clock));
 	max_n = limit->n.max;
-	/* based on hardware requriment prefer smaller n to precision */
-	for (clock.n = limit->n.min; clock.n <= max_n; clock.n++) {
-		/* based on hardware requirment prefere larger m1,m2, p1 */
-		for (clock.m1 = limit->m1.max;
-		     clock.m1 >= limit->m1.min; clock.m1--) {
-			for (clock.m2 = limit->m2.max;
-			     clock.m2 >= limit->m2.min; clock.m2--) {
-				for (clock.p1 = limit->p1.max;
-				     clock.p1 >= limit->p1.min; clock.p1--) {
+	for (clock.p1 = limit->p1.max; clock.p1 >= limit->p1.min; clock.p1--) {
+		/* based on hardware requriment prefer smaller n to precision */
+		for (clock.n = limit->n.min; clock.n <= max_n; clock.n++) {
+			/* based on hardware requirment prefere larger m1,m2 */
+			for (clock.m1 = limit->m1.max;
+			     clock.m1 >= limit->m1.min; clock.m1--) {
+				for (clock.m2 = limit->m2.max;
+				     clock.m2 >= limit->m2.min; clock.m2--) {
 					int this_err;
 
 					intel_clock(dev, refclk, &clock);
@@ -976,8 +1032,12 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
 
 	if (old_fb) {
 		intel_fb = to_intel_framebuffer(old_fb);
+		obj_priv = intel_fb->obj->driver_private;
+		intel_increase_displayclock(crtc);
 		i915_gem_object_unpin(intel_fb->obj);
 	}
+	intel_increase_displayclock(crtc);
+
 	mutex_unlock(&dev->struct_mutex);
 
 	if (!dev->primary->master)
@@ -1855,6 +1915,18 @@ static int intel_get_fifo_size(struct drm_device *dev, int plane)
 	return size;
 }
 
+static void g4x_update_wm(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 fw_blc_self = I915_READ(FW_BLC_SELF);
+
+	if (i915_powersave)
+		fw_blc_self |= FW_BLC_SELF_EN;
+	else
+		fw_blc_self &= ~FW_BLC_SELF_EN;
+	I915_WRITE(FW_BLC_SELF, fw_blc_self);
+}
+
 static void i965_update_wm(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1906,7 +1978,8 @@ static void i9xx_update_wm(struct drm_device *dev, int planea_clock,
 	cwm = 2;
 
 	/* Calc sr entries for one plane configs */
-	if (sr_hdisplay && (!planea_clock || !planeb_clock)) {
+	if (HAS_FW_BLC(dev) && sr_hdisplay &&
+	    (!planea_clock || !planeb_clock)) {
 		/* self-refresh has much higher latency */
 		const static int sr_latency_ns = 6000;
 
@@ -1921,8 +1994,7 @@ static void i9xx_update_wm(struct drm_device *dev, int planea_clock,
 		srwm = total_size - sr_entries;
 		if (srwm < 0)
 			srwm = 1;
-		if (IS_I9XX(dev))
-			I915_WRITE(FW_BLC_SELF, (srwm & 0x3f));
+		I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN | (srwm & 0x3f));
 	}
 
 	DRM_DEBUG("Setting FIFO watermarks - A: %d, B: %d, C: %d, SR %d\n",
@@ -1994,9 +2066,6 @@ static void intel_update_watermarks(struct drm_device *dev)
 	unsigned long planea_clock = 0, planeb_clock = 0, sr_clock = 0;
 	int enabled = 0, pixel_size = 0;
 
-	if (DSPARB_HWCONTROL(dev))
-		return;
-
 	/* Get the clock config from both planes */
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		intel_crtc = to_intel_crtc(crtc);
@@ -2029,7 +2098,9 @@ static void intel_update_watermarks(struct drm_device *dev)
 	else if (IS_IGD(dev))
 		igd_disable_cxsr(dev);
 
-	if (IS_I965G(dev))
+	if (IS_G4X(dev))
+		g4x_update_wm(dev);
+	else if (IS_I965G(dev))
 		i965_update_wm(dev);
 	else if (IS_I9XX(dev) || IS_MOBILE(dev))
 		i9xx_update_wm(dev, planea_clock, planeb_clock, sr_hdisplay,
@@ -2063,9 +2134,9 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 	int dsppos_reg = (pipe == 0) ? DSPAPOS : DSPBPOS;
 	int pipesrc_reg = (pipe == 0) ? PIPEASRC : PIPEBSRC;
 	int refclk, num_outputs = 0;
-	intel_clock_t clock;
-	u32 dpll = 0, fp = 0, dspcntr, pipeconf;
-	bool ok, is_sdvo = false, is_dvo = false;
+	intel_clock_t clock, reduced_clock;
+	u32 dpll = 0, fp = 0, fp2 = 0, dspcntr, pipeconf;
+	bool ok, has_reduced_clock = false, is_sdvo = false, is_dvo = false;
 	bool is_crt = false, is_lvds = false, is_tv = false, is_dp = false;
 	struct drm_mode_config *mode_config = &dev->mode_config;
 	struct drm_connector *connector;
@@ -2143,6 +2214,14 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 		return -EINVAL;
 	}
 
+	if (limit->find_reduced_pll) {
+		memcpy(&reduced_clock, &clock, sizeof(intel_clock_t));
+		has_reduced_clock = limit->find_reduced_pll(limit, crtc,
+							    (adjusted_mode->clock/4),
+							    refclk,
+							    &reduced_clock);
+	}
+
 	/* SDVO TV has fixed PLL values depend on its clock range,
 	   this mirrors vbios setting. */
 	if (is_sdvo && is_tv) {
@@ -2170,10 +2249,17 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 				270000, /* lane clock */
 				&m_n);
 
-	if (IS_IGD(dev))
+	if (IS_IGD(dev)) {
 		fp = (1 << clock.n) << 16 | clock.m1 << 8 | clock.m2;
-	else
+		if (has_reduced_clock)
+			fp2 = (1 << reduced_clock.n) << 16 |
+				reduced_clock.m1 << 8 | reduced_clock.m2;
+	} else {
 		fp = clock.n << 16 | clock.m1 << 8 | clock.m2;
+		if (has_reduced_clock)
+			fp2 = reduced_clock.n << 16 | reduced_clock.m1 << 8 |
+				reduced_clock.m2;
+	}
 
 	if (!IS_IGDNG(dev))
 		dpll = DPLL_VGA_MODE_DIS;
@@ -2202,6 +2288,8 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 			/* also FPA1 */
 			if (IS_IGDNG(dev))
 				dpll |= (1 << (clock.p1 - 1)) << DPLL_FPA1_P1_POST_DIV_SHIFT;
+			if (IS_G4X(dev) && has_reduced_clock)
+				dpll |= (1 << (reduced_clock.p1 - 1)) << DPLL_FPA1_P1_POST_DIV_SHIFT;
 		}
 		switch (clock.p2) {
 		case 5:
@@ -2344,6 +2432,21 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 		intel_dp_set_m_n(crtc, mode, adjusted_mode);
 
 	I915_WRITE(fp_reg, fp);
+	if (has_reduced_clock && i915_powersave) {
+		I915_WRITE(fp_reg + 4, fp2);
+		intel_crtc->lowfreq_avail = true;
+		if (HAS_PIPE_CXSR(dev)) {
+			DRM_DEBUG("enabling CxSR downclocking\n");
+			pipeconf |= PIPECONF_CXSR_DOWNCLOCK;
+		}
+	} else {
+		I915_WRITE(fp_reg + 4, fp);
+		intel_crtc->lowfreq_avail = false;
+		if (HAS_PIPE_CXSR(dev)) {
+			DRM_DEBUG("disabling CxSR downclocking\n");
+			pipeconf &= ~PIPECONF_CXSR_DOWNCLOCK;
+		}
+	}
 	I915_WRITE(dpll_reg, dpll);
 	I915_READ(dpll_reg);
 	/* Wait for the clocks to stabilize. */
@@ -2854,6 +2957,227 @@ struct drm_display_mode *intel_crtc_mode_get(struct drm_device *dev,
 	return mode;
 }
 
+#define GPU_IDLE_TIMEOUT 500 /* ms */
+
+/* When this timer fires, we've been idle for awhile */
+static void intel_gpu_idle_timer(unsigned long arg)
+{
+	struct drm_device *dev = (struct drm_device *)arg;
+	drm_i915_private_t *dev_priv = dev->dev_private;
+
+	DRM_DEBUG("idle timer fired, downclocking\n");
+
+	dev_priv->busy = false;
+
+	schedule_work(&dev_priv->idle_work);
+}
+
+void intel_increase_renderclock(struct drm_device *dev)
+{
+	drm_i915_private_t *dev_priv = dev->dev_private;
+
+	if (IS_G4X(dev) || IS_I9XX(dev)) {
+		u16 gcfgc;
+
+		/* Adjust render clock... */
+		pci_read_config_word(dev->pdev, GCFGC, &gcfgc);
+
+		/* Up to maximum... */
+		gcfgc &= ~0xf;
+		if (IS_G4X(dev))
+			gcfgc |= 0xd;
+		else if (IS_I9XX(dev))
+			gcfgc |= GC_CLOCK_166_250;
+
+		pci_write_config_word(dev->pdev, GCFGC, gcfgc);
+	} else if (IS_I85X(dev)) {
+		u16 hpllcc;
+
+		/* Adjust render clock... */
+		pci_read_config_word(dev->pdev, HPLLCC, &hpllcc);
+
+		/* Up to maximum... */
+		hpllcc &= ~GC_CLOCK_CONTROL_MASK;
+		hpllcc |= GC_CLOCK_166_250;
+
+		pci_write_config_word(dev->pdev, HPLLCC, hpllcc);
+	}
+	DRM_DEBUG("increasing render clock frequency\n");
+
+	/* Schedule downclock */
+	mod_timer(&dev_priv->idle_timer, jiffies +
+		  msecs_to_jiffies(GPU_IDLE_TIMEOUT));
+}
+
+void intel_decrease_renderclock(struct drm_device *dev)
+{
+	if (IS_G4X(dev) || IS_I9XX(dev)) {
+		u16 gcfgc;
+
+		/* Adjust render clock... */
+		pci_read_config_word(dev->pdev, GCFGC, &gcfgc);
+
+		/* Up to maximum... */
+		gcfgc &= ~0xf;
+		gcfgc |= GC_DISPLAY_CLOCK_190_200_MHZ;
+
+		pci_write_config_word(dev->pdev, GCFGC, gcfgc);
+	} else if (IS_I85X(dev)) {
+		u16 hpllcc;
+
+		/* Adjust render clock... */
+		pci_read_config_word(dev->pdev, HPLLCC, &hpllcc);
+
+		/* Up to maximum... */
+		hpllcc &= ~GC_CLOCK_CONTROL_MASK;
+		hpllcc |= GC_CLOCK_133_200;
+
+		pci_write_config_word(dev->pdev, HPLLCC, hpllcc);
+	}
+	DRM_DEBUG("decreasing render clock frequency\n");
+}
+
+#define CRTC_IDLE_TIMEOUT 1000 /* ms */
+
+static void intel_crtc_idle_timer(unsigned long arg)
+{
+	struct intel_crtc *intel_crtc = (struct intel_crtc *)arg;
+	struct drm_crtc *crtc = &intel_crtc->base;
+	drm_i915_private_t *dev_priv = crtc->dev->dev_private;
+
+	DRM_DEBUG("idle timer fired, downclocking\n");
+
+	intel_crtc->busy = false;
+
+	schedule_work(&dev_priv->idle_work);
+}
+
+static void intel_increase_displayclock(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	int pipe = intel_crtc->pipe;
+	int dpll_reg = (pipe == 0) ? DPLL_A : DPLL_B;
+	int dpll = I915_READ(dpll_reg);
+
+	if (!HAS_PIPE_CXSR(dev) && (dpll & DISPLAY_RATE_SELECT_FPA1)) {
+		DRM_DEBUG("upclocking LVDS\n");
+
+		I915_WRITE(dpll_reg, dpll & ~DISPLAY_RATE_SELECT_FPA1);
+		dpll = I915_READ(dpll_reg);
+		intel_wait_for_vblank(dev);
+		dpll = I915_READ(dpll_reg);
+		if (dpll & DISPLAY_RATE_SELECT_FPA1)
+			DRM_DEBUG("failed to upclock LVDS!\n");
+	}
+
+	/* Schedule downclock */
+	mod_timer(&intel_crtc->idle_timer, jiffies +
+		  msecs_to_jiffies(CRTC_IDLE_TIMEOUT));
+}
+
+static void intel_decrease_displayclock(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	int pipe = intel_crtc->pipe;
+	int dpll_reg = (pipe == 0) ? DPLL_A : DPLL_B;
+	int dpll = I915_READ(dpll_reg);
+
+	/*
+	 * Since this is called by a timer, we should never get here in
+	 * the manual case.
+	 */
+	if (!HAS_PIPE_CXSR(dev) && intel_crtc->lowfreq_avail) {
+		DRM_DEBUG("downclocking LVDS\n");
+
+		dpll |= DISPLAY_RATE_SELECT_FPA1;
+		I915_WRITE(dpll_reg, dpll);
+		dpll = I915_READ(dpll_reg);
+		intel_wait_for_vblank(dev);
+		dpll = I915_READ(dpll_reg);
+		if (!(dpll & DISPLAY_RATE_SELECT_FPA1))
+			DRM_DEBUG("failed to downclock LVDS!\n");
+	}
+
+}
+
+/**
+ * intel_idle_update - adjust clocks for idleness
+ * @work: work struct
+ *
+ * Either the GPU or display (or both) went idle.  Check the busy status
+ * here and adjust the CRTC and GPU clocks as necessary.
+ */
+static void intel_idle_update(struct work_struct *work)
+{
+	drm_i915_private_t *dev_priv = container_of(work, drm_i915_private_t,
+						    idle_work);
+	struct drm_device *dev = dev_priv->dev;
+	struct drm_crtc *crtc;
+	struct intel_crtc *intel_crtc;
+
+	if (!i915_powersave)
+		return;
+
+	mutex_lock(&dev->struct_mutex);
+
+	/* GPU isn't processing, downclock it. */
+	if (!dev_priv->busy)
+		intel_decrease_renderclock(dev);
+
+	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+		/* Skip inactive CRTCs */
+		if (!crtc->fb)
+			continue;
+
+		intel_crtc = to_intel_crtc(crtc);
+		if (!intel_crtc->busy)
+			intel_decrease_displayclock(crtc);
+	}
+
+	mutex_unlock(&dev->struct_mutex);
+}
+
+/**
+ * intel_mark_busy - mark the GPU and possibly the display busy
+ * @dev: drm device
+ * @obj: object we're operating on
+ *
+ * Callers can use this function to indicate that the GPU is busy processing
+ * commands.  If @obj matches one of the CRTC objects (i.e. it's a scanout
+ * buffer), we'll also mark the display as busy, so we know to increase its
+ * clock frequency.
+ */
+void intel_mark_busy(struct drm_device *dev, struct drm_gem_object *obj)
+{
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	struct drm_crtc *crtc = NULL;
+	struct intel_framebuffer *intel_fb;
+	struct intel_crtc *intel_crtc;
+
+	dev_priv->busy = true;
+	intel_increase_renderclock(dev);
+
+	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+		if (!crtc->fb)
+			continue;
+
+		intel_crtc = to_intel_crtc(crtc);
+		intel_fb = to_intel_framebuffer(crtc->fb);
+		if (intel_fb->obj == obj) {
+			intel_crtc->busy = true;
+			intel_increase_displayclock(crtc);
+			mod_timer(&intel_crtc->idle_timer, jiffies +
+				  msecs_to_jiffies(CRTC_IDLE_TIMEOUT));
+		}
+	}
+
+
+}
+
 static void intel_crtc_destroy(struct drm_crtc *crtc)
 {
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -2909,6 +3233,10 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
 	intel_crtc->mode_set.crtc = &intel_crtc->base;
 	intel_crtc->mode_set.connectors = (struct drm_connector **)(intel_crtc + 1);
 	intel_crtc->mode_set.num_connectors = 0;
+	intel_crtc->busy = false;
+
+	setup_timer(&intel_crtc->idle_timer, intel_crtc_idle_timer,
+		    (unsigned long)intel_crtc);
 
 	if (i915_fbpercrtc) {
 
@@ -3174,6 +3502,7 @@ static const struct drm_mode_config_funcs intel_mode_funcs = {
 
 void intel_modeset_init(struct drm_device *dev)
 {
+	struct drm_i915_private *dev_priv = dev->dev_private;
 	int num_pipe;
 	int i;
 
@@ -3213,10 +3542,27 @@ void intel_modeset_init(struct drm_device *dev)
 	}
 
 	intel_setup_outputs(dev);
+
+	INIT_WORK(&dev_priv->idle_work, intel_idle_update);
+	setup_timer(&dev_priv->idle_timer, intel_gpu_idle_timer,
+		    (unsigned long)dev);
 }
 
 void intel_modeset_cleanup(struct drm_device *dev)
 {
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	/* Clean up up/down clocking */
+	if (!HAS_PIPE_CXSR(dev)) {
+		u32 dpll_b = I915_READ(DPLL_B);
+
+		del_timer_sync(&dev_priv->idle_timer);
+		dpll_b &= ~DISPLAY_RATE_SELECT_FPA1;
+		I915_WRITE(DPLL_B, dpll_b);
+		POSTING_READ(DPLL_B);
+		intel_wait_for_vblank(dev);
+	}
+
 	drm_mode_config_cleanup(dev);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 004541c..44fe933 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -98,6 +98,9 @@ struct intel_crtc {
 	struct intel_framebuffer *fbdev_fb;
 	/* a mode_set for fbdev users on this crtc */
 	struct drm_mode_set mode_set;
+	bool busy; /* is scanout buffer being updated frequently? */
+	struct timer_list idle_timer;
+	bool lowfreq_avail;
 };
 
 #define to_intel_crtc(x) container_of(x, struct intel_crtc, base)
@@ -116,6 +119,7 @@ extern void intel_hdmi_init(struct drm_device *dev, int sdvox_reg);
 extern bool intel_sdvo_init(struct drm_device *dev, int output_device);
 extern void intel_dvo_init(struct drm_device *dev);
 extern void intel_tv_init(struct drm_device *dev);
+extern void intel_mark_busy(struct drm_device *dev, struct drm_gem_object *obj);
 extern void intel_lvds_init(struct drm_device *dev);
 extern void intel_dp_init(struct drm_device *dev, int dp_reg);
 void
