X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/6f4cc344ab47b720651e5bbf7674951c32e210b1..24f730fce3f2022762011d795c3feada5ef874b3:/Demos/Device/LowLevel/MassStorage/Descriptors.c

diff --git a/Demos/Device/LowLevel/MassStorage/Descriptors.c b/Demos/Device/LowLevel/MassStorage/Descriptors.c
index bb27f2bc6..4dcc4bb26 100644
--- a/Demos/Device/LowLevel/MassStorage/Descriptors.c
+++ b/Demos/Device/LowLevel/MassStorage/Descriptors.c
@@ -37,6 +37,18 @@
 
 #include "Descriptors.h"
 
+/* On some devices, there is a factory set internal serial number which can be automatically sent to the host as
+ * the device's serial number when the Device Descriptor's .SerialNumStrIndex entry is set to USE_INTERNAL_SERIAL.
+ * This allows the host to track a device across insertions on different ports, allowing them to retain allocated
+ * resources like COM port numbers and drivers. On demos using this feature, give a warning on unsupported devices
+ * so that the user can supply their own serial number descriptor instead or remove the USE_INTERNAL_SERIAL value
+ * from the Device Descriptor (forcing the host to generate a serial number for each device from the VID, PID and
+ * port location).
+ */
+#if (USE_INTERNAL_SERIAL == NO_DESCRIPTOR)
+	#warning USE_INTERNAL_SERIAL is not available on this AVR - please manually construct a device serial descriptor.
+#endif
+
 /** Device descriptor structure. This descriptor, located in FLASH memory, describes the overall
  *  device characteristics, including the supported USB version, control endpoint size and the
  *  number of device configurations. The descriptor is read out by the USB host when the enumeration
@@ -107,7 +119,7 @@ USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
 			.Header                 = {.Size = sizeof(USB_Descriptor_Endpoint_t), .Type = DTYPE_Endpoint},
 
 			.EndpointAddress        = (ENDPOINT_DESCRIPTOR_DIR_IN | MASS_STORAGE_IN_EPNUM),
-			.Attributes             = EP_TYPE_BULK,
+			.Attributes             = (EP_TYPE_BULK | ENDPOINT_ATTR_NO_SYNC | ENDPOINT_USAGE_DATA),
 			.EndpointSize           = MASS_STORAGE_IO_EPSIZE,
 			.PollingIntervalMS      = 0x00
 		},
@@ -117,7 +129,7 @@ USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
 			.Header                 = {.Size = sizeof(USB_Descriptor_Endpoint_t), .Type = DTYPE_Endpoint},
 
 			.EndpointAddress        = (ENDPOINT_DESCRIPTOR_DIR_OUT | MASS_STORAGE_OUT_EPNUM),
-			.Attributes             = EP_TYPE_BULK,
+			.Attributes             = (EP_TYPE_BULK | ENDPOINT_ATTR_NO_SYNC | ENDPOINT_USAGE_DATA),
 			.EndpointSize           = MASS_STORAGE_IO_EPSIZE,
 			.PollingIntervalMS      = 0x00
 		}