Fix usbh empty builtin driver warning

Signed-off-by: HiFiPhile <[email protected]>

1 files changed, 5 insertions, 5 deletions

diff --git a/src/host/usbh.c b/src/host/usbh.c
index 2709856bb..e307bb5e5 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -319,13 +319,12 @@ static usbh_class_driver_t const usbh_class_drivers[] = {
   #endif
 };
 
-enum { BUILTIN_DRIVER_COUNT = TU_ARRAY_SIZE(usbh_class_drivers) };
-
 // Additional class drivers implemented by application
 static usbh_class_driver_t const * _app_driver = NULL;
-static uint8_t _app_driver_count = 0;
+static const uint8_t _builtin_driver_count     = TU_ARRAY_SIZE(usbh_class_drivers);
+static uint8_t _app_driver_count               = 0;
 
-#define TOTAL_DRIVER_COUNT    (_app_driver_count + BUILTIN_DRIVER_COUNT)
+#define TOTAL_DRIVER_COUNT    (_app_driver_count + _builtin_driver_count)
 
 // virtually joins built-in and application drivers together.
 // Application is positioned first to allow overwriting built-in ones.
@@ -335,7 +334,7 @@ TU_ATTR_ALWAYS_INLINE static inline usbh_class_driver_t const *get_driver(uint8_
     driver = &_app_driver[drv_id];
   } else {
     drv_id -= _app_driver_count;
-    if (drv_id < BUILTIN_DRIVER_COUNT) {
+    if (_builtin_driver_count > 0 && drv_id < _builtin_driver_count) {
       driver = &usbh_class_drivers[drv_id];
     }
   }
@@ -547,6 +546,7 @@ bool tuh_rhport_init(uint8_t rhport, const tusb_rhport_init_t* rh_init) {
 
     // Get application driver if available
     _app_driver = usbh_app_driver_get_cb(&_app_driver_count);
+    TU_ASSERT(_app_driver_count + _builtin_driver_count <= UINT8_MAX);
 
     // Device
     tu_memclr(_usbh_devices, sizeof(_usbh_devices));