diff --git a/cros_gralloc/cros_gralloc_driver.cc b/cros_gralloc/cros_gralloc_driver.cc
index 06cb653..b1979ac 100644
--- a/cros_gralloc/cros_gralloc_driver.cc
+++ b/cros_gralloc/cros_gralloc_driver.cc
@@ -175,7 +175,7 @@ cros_gralloc_driver::cros_gralloc_driver()
 		if (!drv_render_) {
 			drv_loge("Failed to create driver for the 1st device\n");
 			close(node_fd[0]);
-		} 
+		}
 		switch (availabe_node) {
 		// only have one render node, is GVT-d/BM/VirtIO
 		case 1:
@@ -753,7 +753,7 @@ uint32_t cros_gralloc_driver::get_resolved_drm_format(uint32_t drm_format, uint6
 	uint32_t resolved_format;
 	uint64_t resolved_use_flags;
 	struct driver *drv = drv_render_;
-	
+
 	drv_resolve_format_and_use_flags(drv, drm_format, use_flags, &resolved_format,
 					 &resolved_use_flags);
 
diff --git a/drv.c b/drv.c
index c7eeaae..347c3b7 100644
--- a/drv.c
+++ b/drv.c
@@ -743,11 +743,11 @@ uint32_t drv_resolved_common_drm_format(uint32_t format)
 		case DRM_FORMAT_FLEX_YCbCr_420_888:
 		case DRM_FORMAT_FLEX_IMPLEMENTATION_DEFINED:
 			ret = DRM_FORMAT_NV12;
-			drv_loge("drv_resolved_common_drm_format: DRM_FORMAT_NV12");
+			drv_logi("drv_resolved_common_drm_format: DRM_FORMAT_NV12");
 			break;
 		case DRM_FORMAT_YVU420_ANDROID:
 			ret = DRM_FORMAT_YVU420;
-			drv_loge("drv_resolved_common_drm_format: DRM_FORMAT_YVU420");
+			drv_logi("drv_resolved_common_drm_format: DRM_FORMAT_YVU420");
 			break;
 		default:
 			break;
diff --git a/drv.h b/drv.h
index ac435dc..f786594 100644
--- a/drv.h
+++ b/drv.h
@@ -146,6 +146,7 @@ struct vma {
 	uint32_t map_flags;
 	int32_t refcount;
 	uint32_t map_strides[DRV_MAX_PLANES];
+	bool cpu;
 	void *priv;
 };
 
diff --git a/drv_helpers.c b/drv_helpers.c
index 6fca864..b36447e 100644
--- a/drv_helpers.c
+++ b/drv_helpers.c
@@ -522,6 +522,10 @@ void *drv_dumb_bo_map(struct bo *bo, struct vma *vma, uint32_t map_flags)
 
 int drv_bo_munmap(struct bo *bo, struct vma *vma)
 {
+	if (vma->cpu) {
+		free(vma->addr);
+		vma->addr = NULL;
+	}
 	return munmap(vma->addr, vma->length);
 }
 
@@ -614,6 +618,45 @@ bool drv_has_modifier(const uint64_t *list, uint32_t count, uint64_t modifier)
 	return false;
 }
 
+const u_int16_t ytile_width = 16;
+const u_int16_t ytile_heigth = 32;
+void one_ytile_to_linear(char *src, char *dst, u_int16_t x, u_int16_t y, u_int16_t width, u_int16_t height, uint32_t offset)
+{
+	// x and y follow linear
+	u_int32_t count = x + y * width/ytile_width;
+
+	for (int j = 0; j < ytile_width * ytile_heigth; j += ytile_width) {
+		memcpy(dst + offset + width * ytile_heigth * y + width * j / ytile_width + x * ytile_width,
+			src + offset + j + ytile_width * ytile_heigth * count, ytile_width);
+	}
+}
+
+void * ytiled_to_linear(struct bo_metadata meta, void * src)
+{
+	void* dst = malloc(meta.total_size);
+	if (NULL == dst) return NULL;
+
+	memset(dst, 0, meta.total_size);
+
+	u_int16_t height = meta.sizes[0] / meta.strides[0];
+	// Y
+	u_int16_t y_hcount =  height / ytile_heigth + (height % ytile_heigth != 0);
+	for (u_int16_t x = 0; x < meta.strides[0]/ytile_width; x++) {
+		for (u_int16_t y = 0; y < y_hcount; y++) {
+			one_ytile_to_linear(src, dst, x, y, meta.strides[0], height, 0);
+		}
+	}
+	// UV
+	u_int16_t uv_hcount =  (height/ytile_heigth/2) + (height % (ytile_heigth*2) != 0);
+	for (u_int16_t x = 0; x < meta.strides[0]/ytile_width; x++) {
+		for (u_int16_t y = 0; y < uv_hcount; y++) {
+			one_ytile_to_linear(src, dst, x, y, meta.strides[0], height/2, meta.sizes[0]);
+		}
+	}
+
+	return dst;
+}
+
 void drv_resolve_format_and_use_flags_helper(struct driver *drv, uint32_t format,
 					     uint64_t use_flags, uint32_t *out_format,
 					     uint64_t *out_use_flags)
diff --git a/drv_helpers.h b/drv_helpers.h
index 0ea9ba9..9794d37 100644
--- a/drv_helpers.h
+++ b/drv_helpers.h
@@ -10,7 +10,9 @@
 #include <stdbool.h>
 
 #include "drv.h"
+#include "drv_priv.h"
 #include "drv_array_helpers.h"
+#include <math.h>
 
 #ifndef PAGE_SIZE
 #define PAGE_SIZE 0x1000
@@ -50,4 +52,7 @@ void drv_resolve_format_and_use_flags_helper(struct driver *drv, uint32_t format
 					     uint64_t use_flags, uint32_t *out_format,
 					     uint64_t *out_use_flags);
 
+void one_ytile_to_linear(char *src, char *dst, u_int16_t x, u_int16_t y,
+						u_int16_t width, u_int16_t height, uint32_t offset);
+void *ytiled_to_linear(struct bo_metadata meta, void * src);
 #endif
diff --git a/gbm.c b/gbm.c
index 8dffb14..410a1b2 100644
--- a/gbm.c
+++ b/gbm.c
@@ -63,7 +63,7 @@ PUBLIC struct gbm_device *gbm_create_device(int fd)
 	}
 
 	drv_init(gbm->drv, 0);
-	
+
 	return gbm;
 }
 
diff --git a/i915.c b/i915.c
index 4b7595b..44e3457 100644
--- a/i915.c
+++ b/i915.c
@@ -434,7 +434,7 @@ static int i915_add_combinations(struct driver *drv)
 	if (i915_has_tile4(i915)) {
 		struct format_metadata metadata_4_tiled = { .tiling = I915_TILING_4,
 							    .priority = 3,
-							    .modifier = I915_FORMAT_MOD_4_TILED };	
+							    .modifier = I915_FORMAT_MOD_4_TILED };
 /* Support tile4 NV12 and P010 for libva */
 #ifdef I915_SCANOUT_4_TILED
 		const uint64_t nv12_usage =
@@ -751,7 +751,7 @@ static int i915_init(struct driver *drv)
 	if (!i915_bo_query_prelim_meminfo(drv, i915)) {
 		i915_bo_query_meminfo(drv, i915);
 	} else {
-		drv_loge("drv: kernel supports prelim\n");
+		drv_logi("drv: kernel supports prelim\n");
 	}
 #define FORCE_MEM_PROP "sys.icr.gralloc.force_mem"
 	char prop[PROPERTY_VALUE_MAX];
@@ -759,7 +759,7 @@ static int i915_init(struct driver *drv)
 				property_get(FORCE_MEM_PROP, prop, "local") > 0 &&
 				!strcmp(prop, "local");
 	if (i915->force_mem_local) {
-		drv_loge("Force to use local memory");
+		drv_logi("Force to use local memory");
 	}
 
 	memset(&get_param, 0, sizeof(get_param));
@@ -789,9 +789,9 @@ static int i915_init(struct driver *drv)
 
 	uint64_t width = 0, height = 0;
 	if (drmGetCap(drv->fd, DRM_CAP_CURSOR_WIDTH, &width)) {
-		drv_loge("cannot get cursor width. \n");
+		drv_logi("cannot get cursor width. \n");
 	} else if (drmGetCap(drv->fd, DRM_CAP_CURSOR_HEIGHT, &height)) {
-		drv_loge("cannot get cursor height. \n");
+		drv_logi("cannot get cursor height. \n");
 	}
 
 	if (!width)
@@ -1082,7 +1082,7 @@ static int i915_bo_create_from_metadata(struct bo *bo)
 	struct i915_device *i915 = bo->drv->priv;
 	int64_t use_flags = bo->meta.use_flags;
 	bool local = is_need_local(use_flags);
-	
+
 	if (local && i915->has_local_mem) {
 		if (!is_prelim_kernel) {
 			/* All new BOs we get from the kernel are zeroed, so we don't need to
@@ -1255,6 +1255,7 @@ static void *i915_bo_map(struct bo *bo, struct vma *vma, uint32_t map_flags)
 	int ret;
 	void *addr = MAP_FAILED;
 	struct i915_device *i915 = bo->drv->priv;
+	vma->cpu = false;
 
 	if ((bo->meta.format_modifier == I915_FORMAT_MOD_Y_TILED_CCS) ||
 	    (bo->meta.format_modifier == I915_FORMAT_MOD_Y_TILED_GEN12_RC_CCS) ||
@@ -1298,12 +1299,26 @@ static void *i915_bo_map(struct bo *bo, struct vma *vma, uint32_t map_flags)
 			return MAP_FAILED;
 		}
 
-		drv_loge("%s : %d : handle = %x, size = %zd, mmpa_arg.offset = %llx", __func__,
+		drv_logi("%s : %d : handle = %x, size = %zd, mmpa_arg.offset = %llx", __func__,
 			__LINE__, mmap_arg.handle, bo->meta.total_size, mmap_arg.offset);
 
 		/* And map it */
 		addr = mmap(0, bo->meta.total_size, PROT_READ | PROT_WRITE, MAP_SHARED, bo->drv->fd,
 			    mmap_arg.offset);
+
+		// TODO: GEM_MMAP_OFFSET cannot convert ytiled to linear, we have to convert it manually.
+		// Other formats(e.g. I915_TILING_X) should also be converted.
+		if ((bo->meta.use_flags & (BO_USE_SW_READ_OFTEN | BO_USE_SW_WRITE_OFTEN)) &&
+		    (bo->meta.tiling == I915_TILING_Y)) {
+			void* tmp_addr = ytiled_to_linear(bo->meta, addr);
+
+			if (NULL != tmp_addr) {
+				// release original one and replace it with a linear address.
+				munmap(addr, bo->meta.total_size);
+				addr = tmp_addr;
+				vma->cpu = true;
+			}
+		}
 	} else if (bo->meta.tiling == I915_TILING_NONE) {
 		struct drm_i915_gem_mmap gem_map = { 0 };
 		/* TODO(b/118799155): We don't seem to have a good way to
@@ -1379,7 +1394,7 @@ static int i915_bo_invalidate(struct bo *bo, struct mapping *mapping)
 	int ret;
 	struct drm_i915_gem_set_domain set_domain = { 0 };
 	struct i915_device *i915_dev = (struct i915_device *)bo->drv->priv;
-	
+
 	if (i915_dev->graphics_version != 125) {
 		set_domain.handle = bo->handles[0].u32;
 		if (bo->meta.tiling == I915_TILING_NONE) {