[PATCH 1/2] ASoC: Intel: catpt: Wake up device before configuring SSP port

[Cezary Rojewski]

catpt_dai_pcm_new() invoked during new PCM runtime creation configures
SSP by sending IPC to DSP firmware. For that to succeed device needs to
be up and running. While components default probing behavior -
snd_soc_catpt causing machine board module to load just after it - needs
no changes, machine board's module may be unloaded and re-loaded at a
different time e.g.: when catpt is already asleep.

Wake device explicitly in catpt_dai_pcm_new() to ensure communication is
established before sending any IPCs, enabling those advanced scenarios
in the process.

Signed-off-by: Cezary Rojewski <cezary.rojewski at intel.com>
---

In short, this allows for following scenario (which user usually do not
touch):

1. modprobe snd_soc_catpt // core driver
2. modprobe snd_soc_sst_broadwell // machine board driver
3. wait for snd_soc_catpt to suspend (~2s)
4. rmmod snd_soc_sst_broadwell
5. modprobe snd_soc_sst_broadwell

Without the 3. everything works just fine but let's be more flexible
here.
Right now, -110 (timeout) will occur as device will simply be asleep. To
allow for this advanced scenario, pm_runtime manipulation is required.
memcmp check is to prevent unnecessary operations from occurring.

 sound/soc/intel/catpt/pcm.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sound/soc/intel/catpt/pcm.c b/sound/soc/intel/catpt/pcm.c
index f78018c857b8..ba653ebea7d1 100644
--- a/sound/soc/intel/catpt/pcm.c
+++ b/sound/soc/intel/catpt/pcm.c
@@ -667,7 +667,17 @@ static int catpt_dai_pcm_new(struct snd_soc_pcm_runtime *rtm,
 		break;
 	}
 
+	/* see if this is a new configuration */
+	if (!memcmp(&cdev->devfmt[devfmt.iface], &devfmt, sizeof(devfmt)))
+		return 0;
+
+	pm_runtime_get_sync(cdev->dev);
+
 	ret = catpt_ipc_set_device_format(cdev, &devfmt);
+
+	pm_runtime_mark_last_busy(cdev->dev);
+	pm_runtime_put_autosuspend(cdev->dev);
+
 	if (ret)
 		return CATPT_IPC_ERROR(ret);
 
-- 
2.17.1