diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 8c94040..45d565b 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -2900,3 +2900,18 @@
 	return 0;
 #endif
 }
+
+/**
+ * r600_ioctl_wait_idle - flush host path cache on wait idle ioctl
+ * rdev: radeon device structure
+ * bo: buffer object struct which userspace is waiting for idle
+ *
+ * Some R6XX/R7XX doesn't seems to take into account HDP flush performed
+ * through ring buffer, this leads to corruption in rendering, see
+ * http://bugzilla.kernel.org/show_bug.cgi?id=15186 to avoid this we
+ * directly perform HDP flush by writing register through MMIO.
+ */
+void r600_ioctl_wait_idle(struct radeon_device *rdev, struct radeon_bo *bo)
+{
+	WREG32(R_005480_HDP_MEM_COHERENCY_FLUSH_CNTL, 0x1);
+}
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 2d5f2bf..37150fc 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -661,6 +661,13 @@
 	void (*hpd_fini)(struct radeon_device *rdev);
 	bool (*hpd_sense)(struct radeon_device *rdev, enum radeon_hpd_id hpd);
 	void (*hpd_set_polarity)(struct radeon_device *rdev, enum radeon_hpd_id hpd);
+	/* ioctl hw specific callback. Some hw might want to perform special
+	 * operation on specific ioctl. For instance on wait idle some hw
+	 * might want to perform and HDP flush through MMIO as it seems that
+	 * some R6XX/R7XX hw doesn't take HDP flush into account if programmed
+	 * through ring.
+	 */
+	void (*ioctl_wait_idle)(struct radeon_device *rdev, struct radeon_bo *bo);
 };
 
 /*
diff --git a/drivers/gpu/drm/radeon/radeon_asic.h b/drivers/gpu/drm/radeon/radeon_asic.h
index f2fbd2e..05ee1ae 100644
--- a/drivers/gpu/drm/radeon/radeon_asic.h
+++ b/drivers/gpu/drm/radeon/radeon_asic.h
@@ -117,6 +117,7 @@
 	.hpd_fini = &r100_hpd_fini,
 	.hpd_sense = &r100_hpd_sense,
 	.hpd_set_polarity = &r100_hpd_set_polarity,
+	.ioctl_wait_idle = NULL,
 };
 
 
@@ -176,6 +177,7 @@
 	.hpd_fini = &r100_hpd_fini,
 	.hpd_sense = &r100_hpd_sense,
 	.hpd_set_polarity = &r100_hpd_set_polarity,
+	.ioctl_wait_idle = NULL,
 };
 
 /*
@@ -219,6 +221,7 @@
 	.hpd_fini = &r100_hpd_fini,
 	.hpd_sense = &r100_hpd_sense,
 	.hpd_set_polarity = &r100_hpd_set_polarity,
+	.ioctl_wait_idle = NULL,
 };
 
 
@@ -267,6 +270,7 @@
 	.hpd_fini = &r100_hpd_fini,
 	.hpd_sense = &r100_hpd_sense,
 	.hpd_set_polarity = &r100_hpd_set_polarity,
+	.ioctl_wait_idle = NULL,
 };
 
 
@@ -323,6 +327,7 @@
 	.hpd_fini = &rs600_hpd_fini,
 	.hpd_sense = &rs600_hpd_sense,
 	.hpd_set_polarity = &rs600_hpd_set_polarity,
+	.ioctl_wait_idle = NULL,
 };
 
 
@@ -370,6 +375,7 @@
 	.hpd_fini = &rs600_hpd_fini,
 	.hpd_sense = &rs600_hpd_sense,
 	.hpd_set_polarity = &rs600_hpd_set_polarity,
+	.ioctl_wait_idle = NULL,
 };
 
 
@@ -421,6 +427,7 @@
 	.hpd_fini = &rs600_hpd_fini,
 	.hpd_sense = &rs600_hpd_sense,
 	.hpd_set_polarity = &rs600_hpd_set_polarity,
+	.ioctl_wait_idle = NULL,
 };
 
 
@@ -463,6 +470,7 @@
 	.hpd_fini = &rs600_hpd_fini,
 	.hpd_sense = &rs600_hpd_sense,
 	.hpd_set_polarity = &rs600_hpd_set_polarity,
+	.ioctl_wait_idle = NULL,
 };
 
 /*
@@ -504,6 +512,7 @@
 bool r600_hpd_sense(struct radeon_device *rdev, enum radeon_hpd_id hpd);
 void r600_hpd_set_polarity(struct radeon_device *rdev,
 			   enum radeon_hpd_id hpd);
+extern void r600_ioctl_wait_idle(struct radeon_device *rdev, struct radeon_bo *bo);
 
 static struct radeon_asic r600_asic = {
 	.init = &r600_init,
@@ -538,6 +547,7 @@
 	.hpd_fini = &r600_hpd_fini,
 	.hpd_sense = &r600_hpd_sense,
 	.hpd_set_polarity = &r600_hpd_set_polarity,
+	.ioctl_wait_idle = r600_ioctl_wait_idle,
 };
 
 /*
@@ -582,6 +592,7 @@
 	.hpd_fini = &r600_hpd_fini,
 	.hpd_sense = &r600_hpd_sense,
 	.hpd_set_polarity = &r600_hpd_set_polarity,
+	.ioctl_wait_idle = r600_ioctl_wait_idle,
 };
 
 #endif
diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
index 0e1325e..db8e9a3 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -308,6 +308,9 @@
 	}
 	robj = gobj->driver_private;
 	r = radeon_bo_wait(robj, NULL, false);
+	/* callback hw specific functions if any */
+	if (robj->rdev->asic->ioctl_wait_idle)
+		robj->rdev->asic->ioctl_wait_idle(robj->rdev, robj);
 	mutex_lock(&dev->struct_mutex);
 	drm_gem_object_unreference(gobj);
 	mutex_unlock(&dev->struct_mutex);