+/*
+ * Buggy M-Audio device: running status on input results in a packet that has
+ * the data bytes but not the status byte and that is marked with CIN 4.
+ */
+static void snd_usbmidi_maudio_broken_running_status_input(
+ struct snd_usb_midi_in_endpoint* ep,
+ uint8_t* buffer, int buffer_length)
+{
+ int i;
+
+ for (i = 0; i + 3 < buffer_length; i += 4)
+ if (buffer[i] != 0) {
+ int cable = buffer[i] >> 4;
+ u8 cin = buffer[i] & 0x0f;
+ struct usbmidi_in_port *port = &ep->ports[cable];
+ int length;
+
+ length = snd_usbmidi_cin_length[cin];
+ if (cin == 0xf && buffer[i + 1] >= 0xf8)
+ ; /* realtime msg: no running status change */
+ else if (cin >= 0x8 && cin <= 0xe)
+ /* channel msg */
+ port->running_status_length = length - 1;
+ else if (cin == 0x4 &&
+ port->running_status_length != 0 &&
+ buffer[i + 1] < 0x80)
+ /* CIN 4 that is not a SysEx */
+ length = port->running_status_length;
+ else
+ /*
+ * All other msgs cannot begin running status.
+ * (A channel msg sent as two or three CIN 0xF
+ * packets could in theory, but this device
+ * doesn't use this format.)
+ */
+ port->running_status_length = 0;
+ snd_usbmidi_input_data(ep, cable, &buffer[i + 1], length);
+ }
+}
+
+/*
+ * CME protocol: like the standard protocol, but SysEx commands are sent as a
+ * single USB packet preceded by a 0x0F byte.
+ */
+static void snd_usbmidi_cme_input(struct snd_usb_midi_in_endpoint *ep,
+ uint8_t *buffer, int buffer_length)
+{
+ if (buffer_length < 2 || (buffer[0] & 0x0f) != 0x0f)
+ snd_usbmidi_standard_input(ep, buffer, buffer_length);
+ else
+ snd_usbmidi_input_data(ep, buffer[0] >> 4,
+ &buffer[1], buffer_length - 1);
+}
+