The CDC data interface specifies a USB poll interval of 0. See here:
What effect does this have? i.e. what poll interval will be chosen?
And: is there a reason why this is not configurable as the intervals for the other devices (like KEYBOARD_INTERVAL)?
Code:
#ifdef CDC_DATA_INTERFACE
// interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
9, // bLength
4, // bDescriptorType
CDC_STATUS_INTERFACE, // bInterfaceNumber
...
CDC_DATA_INTERFACE, // bInterfaceNumber
0, // bAlternateSetting
2, // bNumEndpoints
0x0A, // bInterfaceClass
0x00, // bInterfaceSubClass
0x00, // bInterfaceProtocol
0, // iInterface
// endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
7, // bLength
5, // bDescriptorType
CDC_RX_ENDPOINT, // bEndpointAddress
0x02, // bmAttributes (0x02=bulk)
CDC_RX_SIZE, 0, // wMaxPacketSize
0, // bInterval
// endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
7, // bLength
5, // bDescriptorType
CDC_TX_ENDPOINT | 0x80, // bEndpointAddress
0x02, // bmAttributes (0x02=bulk)
CDC_TX_SIZE, 0, // wMaxPacketSize
0, // bInterval
#endif // CDC_DATA_INTERFACE
What effect does this have? i.e. what poll interval will be chosen?
And: is there a reason why this is not configurable as the intervals for the other devices (like KEYBOARD_INTERVAL)?