[PATCH 4/4] ASoC: SOF: Intel: ipc4: Ack a received reply or notification separately

[Peter Ujfalusi]

By acking a received message we tell the DSP that we have processed the
message (reply or notification) and we are open to receive a new one.

The original implementation did this in a common code after the received
message got handled as reply or notification.

With right timing this opens up a small window when we have processed the
reply and let the other thread proceed to send a new message to the DSP,
which is allowed as the DSP is free to receive message.
But when the message is received and processed by the DSP and it wants to
send a reply it will still see that the previous message has not been
acked, so it fails to send a reply. Later the first reply got acked by the
kernel, but it is too late and the in-flight message got a timeout due to
firmware not responding (which it tried, but could not).

Signed-off-by: Peter Ujfalusi <peter.ujfalusi at linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Reviewed-by: Rander Wang <rander.wang at intel.com>
---
 sound/soc/sof/intel/cnl.c     | 7 ++++---
 sound/soc/sof/intel/hda-ipc.c | 7 ++++---
 sound/soc/sof/intel/mtl.c     | 5 +++--
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/sound/soc/sof/intel/cnl.c b/sound/soc/sof/intel/cnl.c
index 4bf233787757..da26f0ce9abc 100644
--- a/sound/soc/sof/intel/cnl.c
+++ b/sound/soc/sof/intel/cnl.c
@@ -72,6 +72,7 @@ irqreturn_t cnl_ipc4_irq_thread(int irq, void *context)
 				spin_lock_irq(&sdev->ipc_lock);
 
 				snd_sof_ipc_get_reply(sdev);
+				cnl_ipc_host_done(sdev);
 				snd_sof_ipc_reply(sdev, data->primary);
 
 				spin_unlock_irq(&sdev->ipc_lock);
@@ -88,10 +89,10 @@ irqreturn_t cnl_ipc4_irq_thread(int irq, void *context)
 			sdev->ipc->msg.rx_data = &notification_data;
 			snd_sof_ipc_msgs_rx(sdev);
 			sdev->ipc->msg.rx_data = NULL;
-		}
 
-		/* Let DSP know that we have finished processing the message */
-		cnl_ipc_host_done(sdev);
+			/* Let DSP know that we have finished processing the message */
+			cnl_ipc_host_done(sdev);
+		}
 
 		ipc_irq = true;
 	}
diff --git a/sound/soc/sof/intel/hda-ipc.c b/sound/soc/sof/intel/hda-ipc.c
index b4668c969a29..a7c454e03952 100644
--- a/sound/soc/sof/intel/hda-ipc.c
+++ b/sound/soc/sof/intel/hda-ipc.c
@@ -169,6 +169,7 @@ irqreturn_t hda_dsp_ipc4_irq_thread(int irq, void *context)
 				spin_lock_irq(&sdev->ipc_lock);
 
 				snd_sof_ipc_get_reply(sdev);
+				hda_dsp_ipc_host_done(sdev);
 				snd_sof_ipc_reply(sdev, data->primary);
 
 				spin_unlock_irq(&sdev->ipc_lock);
@@ -185,10 +186,10 @@ irqreturn_t hda_dsp_ipc4_irq_thread(int irq, void *context)
 			sdev->ipc->msg.rx_data = &notification_data;
 			snd_sof_ipc_msgs_rx(sdev);
 			sdev->ipc->msg.rx_data = NULL;
-		}
 
-		/* Let DSP know that we have finished processing the message */
-		hda_dsp_ipc_host_done(sdev);
+			/* Let DSP know that we have finished processing the message */
+			hda_dsp_ipc_host_done(sdev);
+		}
 
 		ipc_irq = true;
 	}
diff --git a/sound/soc/sof/intel/mtl.c b/sound/soc/sof/intel/mtl.c
index 9d1bc74395e7..054b9ab721ff 100644
--- a/sound/soc/sof/intel/mtl.c
+++ b/sound/soc/sof/intel/mtl.c
@@ -540,6 +540,7 @@ static irqreturn_t mtl_ipc_irq_thread(int irq, void *context)
 				spin_lock_irq(&sdev->ipc_lock);
 
 				snd_sof_ipc_get_reply(sdev);
+				mtl_ipc_host_done(sdev);
 				snd_sof_ipc_reply(sdev, data->primary);
 
 				spin_unlock_irq(&sdev->ipc_lock);
@@ -556,9 +557,9 @@ static irqreturn_t mtl_ipc_irq_thread(int irq, void *context)
 			sdev->ipc->msg.rx_data = &notification_data;
 			snd_sof_ipc_msgs_rx(sdev);
 			sdev->ipc->msg.rx_data = NULL;
-		}
 
-		mtl_ipc_host_done(sdev);
+			mtl_ipc_host_done(sdev);
+		}
 
 		ipc_irq = true;
 	}
-- 
2.38.0