add msc workaround for cxd56

examples/make.mk

@@ -61,6 +61,7 @@ GDB = $(CROSS_COMPILE)gdb
 OBJCOPY = $(CROSS_COMPILE)objcopy
 SIZE = $(CROSS_COMPILE)size
 MKDIR = mkdir
+PYTHON = python
 
 ifeq ($(CMDEXE),1)
   CP = copy

hw/bsp/spresense/board.mk

@@ -70,4 +70,5 @@ $(BUILD)/$(PROJECT).spk: $(MKSPK)
 
 # flash
 flash: $(BUILD)/$(PROJECT).spk
-	@$(TOP)/hw/mcu/sony/cxd56/tools/flash_writer.py -s -c $(SERIAL) -d -b 115200 -n $<
+	@echo FLASH $<
+	@$(PYTHON) $(TOP)/hw/mcu/sony/cxd56/tools/flash_writer.py -s -c $(SERIAL) -d -b 115200 -n $<

src/class/msc/msc_device.c

@@ -611,6 +611,17 @@ bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t
         TU_ASSERT( send_csw(rhport, p_msc) );
       }
     }
+
+    #if TU_CHECK_MCU(CXD56)
+    // WORKAROUND: cxd56 has its own nuttx usb stack which does not forward Set/ClearFeature(Endpoint) to DCD.
+    // There is no way for us to know when EP is un-stall, therefore we will unconditionally un-stall here and
+    // hope everything will work
+    if ( usbd_edpt_stalled(rhport, p_msc->ep_in) )
+    {
+      usbd_edpt_clear_stall(rhport, p_msc->ep_in);
+      send_csw(rhport, p_msc);
+    }
+    #endif
   }
 
   return true;