Add tests for isochronous endpoint descriptors

Author: ianrrees

src/test_class.rs

@@ -32,6 +32,7 @@ pub struct TestClass<'a, B: UsbBus> {
     ep_bulk_out: EndpointOut<'a, B>,
     ep_interrupt_in: EndpointIn<'a, B>,
     ep_interrupt_out: EndpointOut<'a, B>,
+    ep_iso_in: EndpointIn<'a, B>,
     control_buf: [u8; sizes::BUFFER],
     bulk_buf: [u8; sizes::BUFFER],
     interrupt_buf: [u8; sizes::BUFFER],
@@ -72,6 +73,12 @@ impl<B: UsbBus> TestClass<'_, B> {
             ep_bulk_out: alloc.bulk(sizes::BULK_ENDPOINT),
             ep_interrupt_in: alloc.interrupt(sizes::INTERRUPT_ENDPOINT, 1),
             ep_interrupt_out: alloc.interrupt(sizes::INTERRUPT_ENDPOINT, 1),
+            ep_iso_in: alloc.isochronous(
+                IsochronousSynchronizationType::Asynchronous,
+                IsochronousUsageType::ImplicitFeedbackData,
+                500, // These last two args are arbitrary in this usage, they
+                1,   // let the host know how much bandwidth to reserve.
+            ),
             control_buf: [0; sizes::BUFFER],
             bulk_buf: [0; sizes::BUFFER],
             interrupt_buf: [0; sizes::BUFFER],
@@ -218,7 +225,7 @@ impl<B: UsbBus> UsbClass<B> for TestClass<'_, B> {
         writer.endpoint(&self.ep_interrupt_in)?;
         writer.endpoint(&self.ep_interrupt_out)?;
         writer.interface_alt(self.iface, 1, 0xff, 0x01, 0x00, Some(self.interface_string))?;
-
+        writer.endpoint(&self.ep_iso_in)?;
         Ok(())
     }
 

tests/test_class_host/tests.rs

@@ -1,6 +1,6 @@
 use crate::device::*;
 use rand::prelude::*;
-use rusb::{request_type, Direction, Recipient, RequestType};
+use rusb::{request_type, Direction, Recipient, RequestType, TransferType};
 use std::cmp::max;
 use std::fmt::Write;
 use std::time::{Duration, Instant};
@@ -163,6 +163,40 @@ fn interface_descriptor(dev, _out) {
         test_class::INTERFACE_STRING);
 }
 
+fn iso_endpoint_descriptors(dev, _out) {
+    // Tests that an isochronous endpoint descriptor is present in the first
+    // alternate setting, but not in the default setting.
+    let iface = dev.config_descriptor
+        .interfaces()
+        .find(|i| i.number() == 0)
+        .expect("interface not found");
+
+    let mut iso_ep_count = 0;
+    for iface_descriptor in iface.descriptors() {
+        if iface_descriptor.setting_number() == 0 {
+            // Default setting - no isochronous endpoints allowed.  Per USB 2.0
+            // spec rev 2.0, 5.6.3 Isochronous Transfer Packet Size Constraints:
+            //
+            // All device default interface settings must not include any
+            // isochronous endpoints with non-zero data payload sizes (specified
+            // via wMaxPacketSize in the endpoint descriptor)
+            let issue = iface_descriptor
+                .endpoint_descriptors()
+                .find(|ep| ep.transfer_type() == TransferType::Isochronous
+                    && ep.max_packet_size() != 0);
+            if let Some(ep) = issue {
+                panic!("Endpoint {} is isochronous and in the default setting",
+                    ep.number());
+            }
+        } else {
+            iso_ep_count += iface_descriptor.endpoint_descriptors()
+                .filter(|ep| ep.transfer_type() == TransferType::Isochronous)
+                .count();
+        }
+    }
+    assert!(iso_ep_count > 0, "At least one isochronous endpoint is expected");
+}
+
 fn bulk_loopback(dev, _out) {
     let mut lens = vec![0, 1, 2, 32, 63, 64, 65, 127, 128, 129];
     if dev.is_high_speed() {