diff --git a/drivers/char/drm/drm_pciids.h b/drivers/char/drm/drm_pciids.h
index bf9bdc50c1e3..8c16cde91133 100644
--- a/drivers/char/drm/drm_pciids.h
+++ b/drivers/char/drm/drm_pciids.h
@@ -209,6 +209,7 @@
 	{0x1039, 0x0300, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, \
 	{0x1039, 0x5300, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, \
 	{0x1039, 0x6300, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, \
+	{0x1039, 0x6330, PCI_ANY_ID, PCI_ANY_ID, 0, 0, SIS_CHIP_315}, \
 	{0x1039, 0x7300, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, \
 	{0, 0, 0}
 
diff --git a/drivers/char/drm/sis_drv.c b/drivers/char/drm/sis_drv.c
index 93880e449201..3d5b3218b6ff 100644
--- a/drivers/char/drm/sis_drv.c
+++ b/drivers/char/drm/sis_drv.c
@@ -69,6 +69,7 @@ static struct drm_driver driver = {
 	.load = sis_driver_load,
 	.unload = sis_driver_unload,
 	.context_dtor = NULL,
+	.dma_quiescent = sis_idle,
 	.reclaim_buffers = NULL,
 	.reclaim_buffers_locked = sis_reclaim_buffers_locked,
 	.lastclose = sis_lastclose,
diff --git a/drivers/char/drm/sis_drv.h b/drivers/char/drm/sis_drv.h
index 330a2c4eade2..2b8d6f6ed7c0 100644
--- a/drivers/char/drm/sis_drv.h
+++ b/drivers/char/drm/sis_drv.h
@@ -34,13 +34,22 @@
 #define DRIVER_AUTHOR		"SIS, Tungsten Graphics"
 #define DRIVER_NAME		"sis"
 #define DRIVER_DESC		"SIS 300/630/540"
-#define DRIVER_DATE		"20060529"
+#define DRIVER_DATE		"20060704"
 #define DRIVER_MAJOR		1
 #define DRIVER_MINOR		2
 #define DRIVER_PATCHLEVEL	1
 
+enum sis_family {
+	SIS_OTHER = 0,
+	SIS_CHIP_315 = 1,
+};
+
 #include "drm_sman.h"
 
+#define SIS_BASE (dev_priv->mmio)
+#define SIS_READ(reg)         DRM_READ32(SIS_BASE, reg);
+#define SIS_WRITE(reg, val)   DRM_WRITE32(SIS_BASE, reg, val);
+
 typedef struct drm_sis_private {
 	drm_local_map_t *mmio;
 	unsigned int idle_fault;
@@ -52,6 +61,7 @@ typedef struct drm_sis_private {
 	unsigned long agp_offset;
 } drm_sis_private_t;
 
+extern int sis_idle(drm_device_t *dev);
 extern void sis_reclaim_buffers_locked(drm_device_t *dev, struct file *filp);
 extern void sis_lastclose(drm_device_t *dev);
 
diff --git a/drivers/char/drm/sis_mm.c b/drivers/char/drm/sis_mm.c
index 0eb1dca232b7..3041c5b42d56 100644
--- a/drivers/char/drm/sis_mm.c
+++ b/drivers/char/drm/sis_mm.c
@@ -226,6 +226,76 @@ static int sis_ioctl_agp_alloc(DRM_IOCTL_ARGS)
 	return sis_drm_alloc(dev, priv, data, AGP_TYPE);
 }
 
+static drm_local_map_t *sis_reg_init(drm_device_t *dev)
+{
+	drm_map_list_t *entry;
+	drm_local_map_t *map;
+
+	list_for_each_entry(entry, &dev->maplist->head, head) {
+		map = entry->map;
+		if (!map)
+			continue;
+		if (map->type == _DRM_REGISTERS) {
+			return map;
+		}
+	}
+	return NULL;
+}
+
+int sis_idle(drm_device_t *dev)
+{
+	drm_sis_private_t *dev_priv = dev->dev_private;
+	uint32_t idle_reg;
+	unsigned long end;
+	int i;
+
+	if (dev_priv->idle_fault)
+		return 0;
+
+	if (dev_priv->mmio == NULL) {
+		dev_priv->mmio = sis_reg_init(dev);
+		if (dev_priv->mmio == NULL) {
+			DRM_ERROR("Could not find register map.\n");
+			return 0;
+		}
+	}
+	
+	/*
+	 * Implement a device switch here if needed
+	 */
+
+	if (dev_priv->chipset != SIS_CHIP_315)
+		return 0;
+
+	/*
+	 * Timeout after 3 seconds. We cannot use DRM_WAIT_ON here
+	 * because its polling frequency is too low.
+	 */
+
+	end = jiffies + (DRM_HZ * 3);
+
+	for (i=0; i<4; ++i) {
+		do {
+			idle_reg = SIS_READ(0x85cc);
+		} while ( !time_after_eq(jiffies, end) &&
+			  ((idle_reg & 0x80000000) != 0x80000000));
+	}
+
+	if (time_after_eq(jiffies, end)) {
+		DRM_ERROR("Graphics engine idle timeout. "
+			  "Disabling idle check\n");
+		dev_priv->idle_fault = TRUE;
+	}
+
+	/*
+	 * The caller never sees an error code. It gets trapped
+	 * in libdrm.
+	 */
+
+	return 0;
+}
+
+
 void sis_lastclose(struct drm_device *dev)
 {
 	drm_sis_private_t *dev_priv = dev->dev_private;
@@ -237,6 +307,7 @@ void sis_lastclose(struct drm_device *dev)
 	drm_sman_cleanup(&dev_priv->sman);
 	dev_priv->vram_initialized = FALSE;
 	dev_priv->agp_initialized = FALSE;
+	dev_priv->mmio = NULL;
 	mutex_unlock(&dev->struct_mutex);
 }