1<html><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 V1.78.1"><link rel="home" href="index.html" title="Writing an ALSA Driver"><link rel="up" href="midi-interface.html" title="Chapter&#160;8.&#160;MIDI (MPU401-UART) Interface"><link rel="prev" href="midi-interface-constructor.html" title="Constructor"><link rel="next" href="rawmidi-interface.html" title="Chapter&#160;9.&#160;RawMIDI Interface"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><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="midi-interface-constructor.html">Prev</a>&#160;</td><th width="60%" align="center">Chapter&#160;8.&#160;MIDI (MPU401-UART) Interface</th><td width="20%" align="right">&#160;<a accesskey="n" href="rawmidi-interface.html">Next</a></td></tr></table><hr></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="midi-interface-interrupt-handler"></a>Interrupt Handler</h2></div></div></div><p>
2        When the interrupt is allocated in
3      <code class="function">snd_mpu401_uart_new()</code>, an exclusive ISA
4      interrupt handler is automatically used, hence you don't have
5      anything else to do than creating the mpu401 stuff.  Otherwise, you
6      have to set <code class="constant">MPU401_INFO_IRQ_HOOK</code>, and call
7      <code class="function">snd_mpu401_uart_interrupt()</code> explicitly from your
8      own interrupt handler when it has determined that a UART interrupt
9      has occurred.
10      </p><p>
11        In this case, you need to pass the private_data of the
12        returned rawmidi object from
13        <code class="function">snd_mpu401_uart_new()</code> as the second
14        argument of <code class="function">snd_mpu401_uart_interrupt()</code>. 
15
16        </p><div class="informalexample"><pre class="programlisting">
17
18  snd_mpu401_uart_interrupt(irq, rmidi-&gt;private_data, regs);
19
20          </pre></div><p>
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