PLAYBACK_LIST_PTR
ptr = snd_ca0106_ptr_read(emu, PLAYBACK_LIST_PTR, channel);
snd_ca0106_ptr_write(emu, PLAYBACK_LIST_PTR, channel, 0);
snd_emu10k1x_ptr_write(emu, PLAYBACK_LIST_PTR, voice, 0);
ptr3 = snd_emu10k1x_ptr_read(emu, PLAYBACK_LIST_PTR, channel);
ptr4 = snd_emu10k1x_ptr_read(emu, PLAYBACK_LIST_PTR, channel);
snd_emu10k1_ptr20_write(emu, PLAYBACK_LIST_PTR, channel, 0);
ptr3 = snd_emu10k1_ptr20_read(emu, PLAYBACK_LIST_PTR, channel);
ptr4 = snd_emu10k1_ptr20_read(emu, PLAYBACK_LIST_PTR, channel);