Polish thanks to Dan's feedback

.travis.yml

@@ -21,7 +21,7 @@ git:
 # that SDK is shortest and add it there.  In the case of major re-organizations,
 # just try to make the builds "about equal in run time"
 env:
-  - TRAVIS_TESTS="unix docs translations website" TRAVIS_BOARDS="feather_huzzah circuitplayground_express mini_sam_m4 grandcentral_m4_express pca10056 pca10059 feather_nrf52832 feather_nrf52840_express makerdiary_nrf52840_mdk particle_boron particle_argon particle_xenon sparkfun_nrf52840_mini" TRAVIS_SDK=arm:nrf:esp8266
+  - TRAVIS_TESTS="unix docs translations website" TRAVIS_BOARDS="feather_huzzah circuitplayground_express mini_sam_m4 grandcentral_m4_express pca10056 pca10059 feather_nrf52840_express makerdiary_nrf52840_mdk particle_boron particle_argon particle_xenon sparkfun_nrf52840_mini" TRAVIS_SDK=arm:nrf:esp8266
   - TRAVIS_BOARDS="metro_m0_express metro_m4_express pirkey_m0 trellis_m4_express trinket_m0" TRAVIS_SDK=arm
   - TRAVIS_BOARDS="feather_radiofruit_zigbee gemma_m0 hallowing_m0_express itsybitsy_m0_express itsybitsy_m4_express meowmeow" TRAVIS_SDK=arm
   - TRAVIS_BOARDS="feather_m0_express_crickit feather_m0_rfm69 feather_m0_rfm9x feather_m4_express arduino_zero arduino_mkr1300 arduino_mkrzero" TRAVIS_SDK=arm

shared-bindings/usb_midi/PortIn.c

@@ -45,6 +45,9 @@
 //|
 //|   Not currently dynamically supported.
 //|
+//|   PortIn objects are constructed for every corresponding entry in the USB descriptor and added
+//|   to the `usb_midi.ports` tuple.
+//|
 
 STATIC mp_obj_t usb_midi_portin_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *pos_args) {
     return mp_const_none;

shared-bindings/usb_midi/PortOut.c

@@ -45,6 +45,9 @@
 //|
 //|   Not currently dynamically supported.
 //|
+//|   PortOut objects are constructed for every corresponding entry in the USB descriptor and added
+//|   to the `usb_midi.ports` tuple.
+//|
 
 STATIC mp_obj_t usb_midi_portout_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *pos_args) {
     return mp_const_none;

shared-module/usb_midi/__init__.c

@@ -38,18 +38,11 @@
 
 supervisor_allocation* usb_midi_allocation;
 
-static inline uint16_t word_align(uint16_t size) {
-    if (size % 4 != 0) {
-        return (size & 0xfffc) + 0x4;
-    }
-    return size;
-}
-
 void usb_midi_init(void) {
     // TODO(tannewt): Make this dynamic.
-    uint16_t tuple_size = word_align(sizeof(mp_obj_tuple_t) + sizeof(mp_obj_t*) * 2);
-    uint16_t portin_size = word_align(sizeof(usb_midi_portin_obj_t));
-    uint16_t portout_size = word_align(sizeof(usb_midi_portout_obj_t));
+    uint16_t tuple_size = align32_size(sizeof(mp_obj_tuple_t) + sizeof(mp_obj_t*) * 2);
+    uint16_t portin_size = align32_size(sizeof(usb_midi_portin_obj_t));
+    uint16_t portout_size = align32_size(sizeof(usb_midi_portout_obj_t));
 
     // For each embedded MIDI Jack in the descriptor we create a Port
     usb_midi_allocation = allocate_memory(tuple_size + portin_size + portout_size, false);

supervisor/memory.h

@@ -39,6 +39,8 @@ typedef struct {
     uint32_t length; // in bytes
 } supervisor_allocation;
 
+
+
 void memory_init(void);
 void free_memory(supervisor_allocation* allocation);
 supervisor_allocation* allocate_remaining_memory(void);
@@ -48,4 +50,11 @@ supervisor_allocation* allocate_remaining_memory(void);
 // statically allocated memory.
 supervisor_allocation* allocate_memory(uint32_t length, bool high_address);
 
+static inline uint16_t align32_size(uint16_t size) {
+    if (size % 4 != 0) {
+        return (size & 0xfffc) + 0x4;
+    }
+    return size;
+}
+
 #endif  // MICROPY_INCLUDED_SUPERVISOR_MEMORY_H

tools/gen_usb_descriptor.py

@@ -274,6 +274,8 @@ descriptor_list = []
 descriptor_list.append(cdc_iad)
 descriptor_list.extend(cdc_interfaces)
 descriptor_list.extend(msc_interfaces)
+# Only add the control interface because other audio interfaces are managed by it to ensure the
+# correct ordering.
 descriptor_list.append(audio_control_interface)
 # Put the CDC IAD just before the CDC interfaces.
 # There appears to be a bug in the Windows composite USB driver that requests the