+ <para>
+ When the controller supports only the input or output MIDI stream,
+ pass <constant>MPU401_INFO_INPUT</constant> or
+ <constant>MPU401_INFO_OUTPUT</constant> bitflag, respectively.
+ Then the rawmidi instance is created as a single stream.
+ </para>
+
+ <para>
+ <constant>MPU401_INFO_MMIO</constant> bitflag is used to change
+ the access method to MMIO (via readb and writeb) instead of
+ iob and outb. In this case, you have to pass the iomapped address
+ to <function>snd_mpu401_uart_new()</function>.
+ </para>
+
+ <para>
+ When <constant>MPU401_INFO_TX_IRQ</constant> is set, the output
+ stream isn't checked in the default interrupt handler. The driver
+ needs to call <function>snd_mpu401_uart_interrupt_tx()</function>
+ by itself to start processing the output stream in irq handler.
+ </para>
+