 open procedure succeeded, return zero. Otherwise,
return -errno.
<H4>
7.2.2 Ioctl Callback</H4>
The <TT>ioctl</TT> callback is called when the sequencer receives device-specific
ioctls. The following two ioctls should be processed by this callback:
<UL>
<LI>
<TT>IOCTL_SEQ_RESET_SAMPLES</TT></LI>

<BR>reset all samples on memory -- return 0
<LI>
<TT>IOCTL_SYNTH_MEMAVL</TT></LI>

<BR>return the available memory size
<LI>
<TT>FM_4OP_ENABLE</TT></LI>

<BR>can be ignored usually</UL>
The other ioctls are proces