diff --git a/drivers/video/rockchip/vcodec/vcodec_iommu_drm.c b/drivers/video/rockchip/vcodec/vcodec_iommu_drm.c
index 9ad03507d8bb..d10e2e0650cc 100644
--- a/drivers/video/rockchip/vcodec/vcodec_iommu_drm.c
+++ b/drivers/video/rockchip/vcodec/vcodec_iommu_drm.c
@@ -34,6 +34,7 @@
 #include <linux/console.h>
 #include <linux/kref.h>
 #include <linux/fdtable.h>
+#include <linux/ktime.h>
 
 #include "vcodec_iommu_ops.h"
 
@@ -52,6 +53,7 @@ struct vcodec_drm_buffer {
 	struct page **pages;
 	struct kref ref;
 	struct vcodec_iommu_session_info *session_info;
+	ktime_t last_used;
 };
 
 struct vcodec_iommu_drm_info {
@@ -67,8 +69,10 @@ vcodec_drm_get_buffer_no_lock(struct vcodec_iommu_session_info *session_info,
 
 	list_for_each_entry_safe(drm_buffer, n, &session_info->buffer_list,
 				 list) {
-		if (drm_buffer->index == idx)
+		if (drm_buffer->index == idx) {
+			drm_buffer->last_used = ktime_get();
 			return drm_buffer;
+		}
 	}
 
 	return NULL;
@@ -86,6 +90,7 @@ vcodec_drm_get_buffer_fd_no_lock(struct vcodec_iommu_session_info *session_info,
 	list_for_each_entry_safe(drm_buffer, n, &session_info->buffer_list,
 				 list) {
 		if (drm_buffer->dma_buf == dma_buf) {
+			drm_buffer->last_used = ktime_get();
 			dma_buf_put(dma_buf);
 			return drm_buffer;
 		}
@@ -276,6 +281,7 @@ static int vcodec_drm_free(struct vcodec_iommu_session_info *session_info,
 		dma_buf_put(drm_buffer->dma_buf);
 		list_del_init(&drm_buffer->list);
 		kfree(drm_buffer);
+		session_info->buffer_nums--;
 	}
 	mutex_unlock(&session_info->list_mutex);
 
@@ -386,6 +392,7 @@ vcodec_drm_free_fd(struct vcodec_iommu_session_info *session_info, int fd)
 		dma_buf_put(drm_buffer->dma_buf);
 		list_del_init(&drm_buffer->list);
 		kfree(drm_buffer);
+		session_info->buffer_nums--;
 	}
 	mutex_unlock(&session_info->list_mutex);
 
@@ -432,12 +439,15 @@ static int vcodec_drm_import(struct vcodec_iommu_session_info *session_info,
 			     int fd)
 {
 	struct vcodec_drm_buffer *drm_buffer = NULL, *n;
+	struct vcodec_drm_buffer *oldest_buffer = NULL, *loop_buffer = NULL;
 	struct vcodec_iommu_info *iommu_info = session_info->iommu_info;
 	struct vcodec_iommu_drm_info *drm_info = iommu_info->private;
+	struct iommu_domain *domain = drm_info->domain;
 	struct device *dev = session_info->dev;
 	struct dma_buf_attachment *attach;
 	struct sg_table *sgt;
 	struct dma_buf *dma_buf;
+	ktime_t oldest_time = ktime_set(0, 0);
 	int ret = 0;
 
 	dma_buf = dma_buf_get(fd);
@@ -450,6 +460,7 @@ static int vcodec_drm_import(struct vcodec_iommu_session_info *session_info,
 				 &session_info->buffer_list, list) {
 		if (drm_buffer->dma_buf == dma_buf) {
 			dma_buf_put(dma_buf);
+			drm_buffer->last_used = ktime_get();
 			return drm_buffer->index;
 		}
 	}
@@ -462,6 +473,7 @@ static int vcodec_drm_import(struct vcodec_iommu_session_info *session_info,
 
 	drm_buffer->dma_buf = dma_buf;
 	drm_buffer->session_info = session_info;
+	drm_buffer->last_used = ktime_get();
 
 	kref_init(&drm_buffer->ref);
 
@@ -493,10 +505,30 @@ static int vcodec_drm_import(struct vcodec_iommu_session_info *session_info,
 	drm_buffer->attach = attach;
 	drm_buffer->sgt = sgt;
 
+	if (!drm_info->attached)
+		iommu_detach_device(domain, dev);
+
 	mutex_unlock(&iommu_info->iommu_mutex);
 
 	INIT_LIST_HEAD(&drm_buffer->list);
 	mutex_lock(&session_info->list_mutex);
+	session_info->buffer_nums++;
+	if (session_info->buffer_nums > BUFFER_LIST_MAX_NUMS) {
+		list_for_each_entry_safe(loop_buffer, n,
+				 &session_info->buffer_list, list) {
+			if (ktime_to_ns(oldest_time) == 0 ||
+			    ktime_after(oldest_time,
+					loop_buffer->last_used)) {
+				oldest_time = loop_buffer->last_used;
+				oldest_buffer = loop_buffer;
+			}
+		}
+		kref_put(&oldest_buffer->ref, vcodec_drm_clear_map);
+		dma_buf_put(oldest_buffer->dma_buf);
+		list_del_init(&oldest_buffer->list);
+		kfree(oldest_buffer);
+		session_info->buffer_nums--;
+	}
 	drm_buffer->index = session_info->max_idx;
 	list_add_tail(&drm_buffer->list, &session_info->buffer_list);
 	session_info->max_idx++;
diff --git a/drivers/video/rockchip/vcodec/vcodec_iommu_ops.c b/drivers/video/rockchip/vcodec/vcodec_iommu_ops.c
index 384c8ce7b97e..bb25db4d2656 100644
--- a/drivers/video/rockchip/vcodec/vcodec_iommu_ops.c
+++ b/drivers/video/rockchip/vcodec/vcodec_iommu_ops.c
@@ -63,6 +63,7 @@ int vcodec_iommu_import(struct vcodec_iommu_info *iommu_info,
 		session_info->mmu_dev = iommu_info->mmu_dev;
 		session_info->dev = iommu_info->dev;
 		session_info->iommu_info = iommu_info;
+		session_info->buffer_nums = 0;
 		mutex_lock(&iommu_info->list_mutex);
 		list_add_tail(&session_info->head, &iommu_info->session_list);
 		mutex_unlock(&iommu_info->list_mutex);
diff --git a/drivers/video/rockchip/vcodec/vcodec_iommu_ops.h b/drivers/video/rockchip/vcodec/vcodec_iommu_ops.h
index 86069985c13d..46c721a9094b 100644
--- a/drivers/video/rockchip/vcodec/vcodec_iommu_ops.h
+++ b/drivers/video/rockchip/vcodec/vcodec_iommu_ops.h
@@ -19,6 +19,8 @@
 #include <linux/platform_device.h>
 #include "vcodec_service.h"
 
+#define BUFFER_LIST_MAX_NUMS	30
+
 #define ALLOCATOR_USE_ION		0x00000000
 #define ALLOCATOR_USE_DRM		0x00000001
 
@@ -65,6 +67,7 @@ struct vcodec_iommu_ops {
 struct vcodec_iommu_session_info {
 	struct list_head head;
 	struct vpu_session *session;
+	int buffer_nums;
 	struct list_head buffer_list;
 	struct mutex list_mutex;
 	int max_idx;