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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>Interrupt Handler</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="Writing an ALSA Driver" /><link rel="up" href="ch08.html" title="Chapter 8. MIDI (MPU401-UART) Interface" /><link rel="prev" href="ch08s02.html" title="Constructor" /><link rel="next" href="ch09.html" title="Chapter 9. RawMIDI Interface" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Interrupt Handler</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch08s02.html">Prev</a> </td><th width="60%" align="center">Chapter 8. MIDI (MPU401-UART) Interface</th><td width="20%" align="right"> <a accesskey="n" href="ch09.html">Next</a></td></tr></table><hr /></div><div class="section" title="Interrupt Handler"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="midi-interface-interrupt-handler"></a>Interrupt Handler</h2></div></div></div><p>
When the interrupt is allocated in
<code class="function">snd_mpu401_uart_new()</code>, the private
interrupt handler is used, hence you don't have anything else to do
than creating the mpu401 stuff. Otherwise, you have to call
<code class="function">snd_mpu401_uart_interrupt()</code> explicitly when
a UART interrupt is invoked and checked in your own interrupt
handler.
</p><p>
In this case, you need to pass the private_data of the
returned rawmidi object from
<code class="function">snd_mpu401_uart_new()</code> as the second
argument of <code class="function">snd_mpu401_uart_interrupt()</code>.
</p><div class="informalexample"><pre class="programlisting">
snd_mpu401_uart_interrupt(irq, rmidi->private_data, regs);
</pre></div><p>
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