ASoC: msm8974: fall back to have AFE port started at prepare

After upgrading to kernel 3.4, there is 5 second delay
at the closing of PCM playback. The delay is due to missing
EOS from QDSP6 audio session manager causing pcm close function
of PCM platform driver to wait for 5 seconds. The root cause
for missing EOS is that ALSA dynmic PCM shutdown sequence has
changed. Now, trigger stop is called on the back-end DAI-LINK.
Furthermore, back-end trigger stop is called before front-end
trigger stop. Since sink stops rendering data, data at source
will never get consumed. EOS event will not arrive. As trigger
operation has to be atomic, it is very difficult to guarantee
sequence on shutting down various modules in QDSP6. The decision
is to abandon starting and stopping QDSP6 AFE port in trigger
function. This decision is considered acceptable as playback
and capture over SLIMBUS is no longer subject to strict sequence
which Q6 AFE port must be started after CODEC configuration.

Change-Id: Ief351168b08d5cca0a76405834cf3d6aa14a3941
Signed-off-by: Phani Kumar Uppalapati <phanik@codeaurora.org>
diff --git a/include/sound/q6afe-v2.h b/include/sound/q6afe-v2.h
index b1ed9a4..8ccc9f4 100644
--- a/include/sound/q6afe-v2.h
+++ b/include/sound/q6afe-v2.h
@@ -92,7 +92,7 @@
 int afe_unregister_get_events(u16 port_id);
 int afe_rt_proxy_port_write(u32 buf_addr_p, u32 mem_map_handle, int bytes);
 int afe_rt_proxy_port_read(u32 buf_addr_p, u32 mem_map_handle, int bytes);
-int afe_port_start_nowait(u16 port_id, union afe_port_config *afe_config,
+int afe_port_start(u16 port_id, union afe_port_config *afe_config,
 	u32 rate);
 int afe_port_stop_nowait(int port_id);
 int afe_apply_gain(u16 port_id, u16 gain);