diff --git a/platform/fatfs/usbh_fatfs.c b/platform/fatfs/usbh_fatfs.c
index 1d7aff38..abb7181b 100644
--- a/platform/fatfs/usbh_fatfs.c
+++ b/platform/fatfs/usbh_fatfs.c
@@ -34,7 +34,7 @@ int USB_disk_read(BYTE *buff, LBA_t sector, UINT count)
     uint8_t *align_buf;
 
     align_buf = (uint8_t *)buff;
-#ifdef CONFIG_USB_DCACHE_ENABLE
+
     if ((uint32_t)buff & (CONFIG_USB_ALIGN_SIZE - 1)) {
         align_buf = (uint8_t *)aligned_alloc(CONFIG_USB_ALIGN_SIZE, count * active_msc_class->blocksize);
         if (!align_buf) {
@@ -42,19 +42,19 @@ int USB_disk_read(BYTE *buff, LBA_t sector, UINT count)
             return -USB_ERR_NOMEM;
         }
     }
-#endif
+
     ret = usbh_msc_scsi_read10(active_msc_class, sector, align_buf, count);
     if (ret < 0) {
         ret = RES_ERROR;
     } else {
         ret = RES_OK;
     }
-#ifdef CONFIG_USB_DCACHE_ENABLE
+
     if ((uint32_t)buff & (CONFIG_USB_ALIGN_SIZE - 1)) {
         usb_memcpy(buff, align_buf, count * active_msc_class->blocksize);
         free(align_buf);
     }
-#endif
+
     return ret;
 }
 
@@ -64,7 +64,7 @@ int USB_disk_write(const BYTE *buff, LBA_t sector, UINT count)
     uint8_t *align_buf;
 
     align_buf = (uint8_t *)buff;
-#ifdef CONFIG_USB_DCACHE_ENABLE
+
     if ((uint32_t)buff & (CONFIG_USB_ALIGN_SIZE - 1)) {
         align_buf = (uint8_t *)aligned_alloc(CONFIG_USB_ALIGN_SIZE, count * active_msc_class->blocksize);
         if (!align_buf) {
@@ -73,18 +73,18 @@ int USB_disk_write(const BYTE *buff, LBA_t sector, UINT count)
         }
         usb_memcpy(align_buf, buff, count * active_msc_class->blocksize);
     }
-#endif
+
     ret = usbh_msc_scsi_write10(active_msc_class, sector, align_buf, count);
     if (ret < 0) {
         ret = RES_ERROR;
     } else {
         ret = RES_OK;
     }
-#ifdef CONFIG_USB_DCACHE_ENABLE
+
     if ((uint32_t)buff & (CONFIG_USB_ALIGN_SIZE - 1)) {
         free(align_buf);
     }
-#endif
+
     return ret;
 }
 
diff --git a/platform/rtthread/usbd_serial.c b/platform/rtthread/usbd_serial.c
index aeb53a9b..2f6d484b 100644
--- a/platform/rtthread/usbd_serial.c
+++ b/platform/rtthread/usbd_serial.c
@@ -76,9 +76,8 @@ static rt_err_t usbd_serial_open(struct rt_device *dev, rt_uint16_t oflag)
 
     serial = (struct usbd_serial *)dev;
 
-    if (!usb_device_is_configured(serial->busid)) {
-        USB_LOG_ERR("USB device is not configured\n");
-        return -RT_EPERM;
+    while(!usb_device_is_configured(serial->busid)) {
+        rt_thread_mdelay(10);
     }
 
     usbd_ep_start_read(serial->busid, serial->out_ep,
@@ -123,9 +122,8 @@ static rt_ssize_t usbd_serial_write(struct rt_device *dev,
     }
     align_buf = (rt_uint8_t *)buffer;
 
-#ifdef CONFIG_USB_DCACHE_ENABLE
     if ((uint32_t)buffer & (CONFIG_USB_ALIGN_SIZE - 1)) {
-        align_buf = rt_malloc_align(size, CONFIG_USB_ALIGN_SIZE);
+        align_buf = rt_malloc_align(USB_ALIGN_UP(size, CONFIG_USB_ALIGN_SIZE), CONFIG_USB_ALIGN_SIZE);
         if (!align_buf) {
             USB_LOG_ERR("serial get align buf failed\n");
             return 0;
@@ -133,7 +131,7 @@ static rt_ssize_t usbd_serial_write(struct rt_device *dev,
 
         usb_memcpy(align_buf, buffer, size);
     }
-#endif
+
     usb_osal_sem_reset(serial->tx_done);
     usbd_ep_start_write(serial->busid, serial->in_ep, align_buf, size);
     ret = usb_osal_sem_take(serial->tx_done, 3000);
@@ -144,11 +142,9 @@ static rt_ssize_t usbd_serial_write(struct rt_device *dev,
         ret = size;
     }
 
-#ifdef CONFIG_USB_DCACHE_ENABLE
     if ((uint32_t)buffer & (CONFIG_USB_ALIGN_SIZE - 1)) {
         rt_free_align(align_buf);
     }
-#endif
 
     return ret;
 }
diff --git a/platform/rtthread/usbh_dfs.c b/platform/rtthread/usbh_dfs.c
index 1344f539..77846665 100644
--- a/platform/rtthread/usbh_dfs.c
+++ b/platform/rtthread/usbh_dfs.c
@@ -38,7 +38,7 @@ static rt_ssize_t rt_udisk_read(rt_device_t dev, rt_off_t pos, void *buffer,
     rt_uint8_t *align_buf;
 
     align_buf = (rt_uint8_t *)buffer;
-#ifdef CONFIG_USB_DCACHE_ENABLE
+
     if ((uint32_t)buffer & (CONFIG_USB_ALIGN_SIZE - 1)) {
         align_buf = rt_malloc_align(size * msc_class->blocksize, CONFIG_USB_ALIGN_SIZE);
         if (!align_buf) {
@@ -47,18 +47,18 @@ static rt_ssize_t rt_udisk_read(rt_device_t dev, rt_off_t pos, void *buffer,
         }
     } else {
     }
-#endif
+
     ret = usbh_msc_scsi_read10(msc_class, pos, (uint8_t *)align_buf, size);
     if (ret < 0) {
         rt_kprintf("usb mass_storage read failed\n");
         return 0;
     }
-#ifdef CONFIG_USB_DCACHE_ENABLE
+
     if ((uint32_t)buffer & (CONFIG_USB_ALIGN_SIZE - 1)) {
         usb_memcpy(buffer, align_buf, size * msc_class->blocksize);
         rt_free_align(align_buf);
     }
-#endif
+
     return size;
 }
 
@@ -70,7 +70,7 @@ static rt_ssize_t rt_udisk_write(rt_device_t dev, rt_off_t pos, const void *buff
     rt_uint8_t *align_buf;
 
     align_buf = (rt_uint8_t *)buffer;
-#ifdef CONFIG_USB_DCACHE_ENABLE
+
     if ((uint32_t)buffer & (CONFIG_USB_ALIGN_SIZE - 1)) {
         align_buf = rt_malloc_align(size * msc_class->blocksize, CONFIG_USB_ALIGN_SIZE);
         if (!align_buf) {
@@ -80,17 +80,16 @@ static rt_ssize_t rt_udisk_write(rt_device_t dev, rt_off_t pos, const void *buff
 
         usb_memcpy(align_buf, buffer, size * msc_class->blocksize);
     }
-#endif
+
     ret = usbh_msc_scsi_write10(msc_class, pos, (uint8_t *)align_buf, size);
     if (ret < 0) {
         rt_kprintf("usb mass_storage write failed\n");
         return 0;
     }
-#ifdef CONFIG_USB_DCACHE_ENABLE
+
     if ((uint32_t)buffer & (CONFIG_USB_ALIGN_SIZE - 1)) {
         rt_free_align(align_buf);
     }
-#endif
 
     return size;
 }
diff --git a/platform/rtthread/usbh_serial.c b/platform/rtthread/usbh_serial.c
index cbfbc49e..912258e0 100644
--- a/platform/rtthread/usbh_serial.c
+++ b/platform/rtthread/usbh_serial.c
@@ -193,9 +193,9 @@ static rt_ssize_t usbh_serial_write(struct rt_device *dev,
     serial = (struct usbh_serial *)dev;
 
     align_buf = (rt_uint8_t *)buffer;
-#ifdef CONFIG_USB_DCACHE_ENABLE
+
     if ((uint32_t)buffer & (CONFIG_USB_ALIGN_SIZE - 1)) {
-        align_buf = rt_malloc_align(size, CONFIG_USB_ALIGN_SIZE);
+        align_buf = rt_malloc_align(USB_ALIGN_UP(size, CONFIG_USB_ALIGN_SIZE), CONFIG_USB_ALIGN_SIZE);
         if (!align_buf) {
             USB_LOG_ERR("serial get align buf failed\n");
             return 0;
@@ -203,7 +203,6 @@ static rt_ssize_t usbh_serial_write(struct rt_device *dev,
 
         usb_memcpy(align_buf, buffer, size);
     }
-#endif
 
     switch (serial->type) {
 #if defined(PKG_CHERRYUSB_HOST_CDC_ACM) || defined(RT_CHERRYUSB_HOST_CDC_ACM)
@@ -211,10 +210,7 @@ static rt_ssize_t usbh_serial_write(struct rt_device *dev,
             ret = usbh_cdc_acm_bulk_out_transfer((struct usbh_cdc_acm *)dev->user_data, (uint8_t *)align_buf, size, RT_WAITING_FOREVER);
             if (ret < 0) {
                 USB_LOG_ERR("usbh_cdc_acm_bulk_out_transfer failed: %d\n", ret);
-#ifdef CONFIG_USB_DCACHE_ENABLE
-                rt_free_align(align_buf);
-#endif
-                return 0;
+                ret = 0;
             }
             break;
 #endif
@@ -223,10 +219,7 @@ static rt_ssize_t usbh_serial_write(struct rt_device *dev,
             ret = usbh_ftdi_bulk_out_transfer((struct usbh_ftdi *)dev->user_data, (uint8_t *)align_buf, size, RT_WAITING_FOREVER);
             if (ret < 0) {
                 USB_LOG_ERR("usbh_ftdi_bulk_out_transfer failed: %d\n", ret);
-#ifdef CONFIG_USB_DCACHE_ENABLE
-                rt_free_align(align_buf);
-#endif
-                return 0;
+                ret = 0;
             }
             break;
 #endif
@@ -235,10 +228,7 @@ static rt_ssize_t usbh_serial_write(struct rt_device *dev,
             ret = usbh_ch34x_bulk_out_transfer((struct usbh_ch34x *)dev->user_data, (uint8_t *)align_buf, size, RT_WAITING_FOREVER);
             if (ret < 0) {
                 USB_LOG_ERR("usbh_ch34x_bulk_out_transfer failed: %d\n", ret);
-#ifdef CONFIG_USB_DCACHE_ENABLE
-                rt_free_align(align_buf);
-#endif
-                return 0;
+                ret = 0;
             }
             break;
 #endif
@@ -247,10 +237,7 @@ static rt_ssize_t usbh_serial_write(struct rt_device *dev,
             ret = usbh_pl2303_bulk_out_transfer((struct usbh_pl2303 *)dev->user_data, (uint8_t *)align_buf, size, RT_WAITING_FOREVER);
             if (ret < 0) {
                 USB_LOG_ERR("usbh_pl2303_bulk_out_transfer failed: %d\n", ret);
-#ifdef CONFIG_USB_DCACHE_ENABLE
-                rt_free_align(align_buf);
-#endif
-                return 0;
+                ret = 0;
             }
             break;
 #endif
@@ -258,11 +245,9 @@ static rt_ssize_t usbh_serial_write(struct rt_device *dev,
             break;
     }
 
-#ifdef CONFIG_USB_DCACHE_ENABLE
     if ((uint32_t)buffer & (CONFIG_USB_ALIGN_SIZE - 1)) {
         rt_free_align(align_buf);
     }
-#endif
 
     return ret;
 }