From 072f6348c589150cab9b1bc53b4e82bb0e332748 Mon Sep 17 00:00:00 2001
From: Jai Luthra <j-luthra@ti.com>
Date: Tue, 11 Jun 2024 18:02:55 +0530
Subject: [PATCH] ALSA: dmaengine: Synchronize dma channel after drop()
[ Upstream commit e8343410ddf08fc36a9b9cc7c51a4e53a262d4c6 ]
Sometimes the stream may be stopped due to XRUN events, in which case
the userspace can call snd_pcm_drop() and snd_pcm_prepare() to stop and
start the stream again.
In these cases, we must wait for the DMA channel to synchronize before
marking the stream as prepared for playback, as the DMA channel gets
stopped by drop() without any synchronization. Make sure the ALSA core
synchronizes the DMA channel by adding a sync_stop() hook.
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Link: https://lore.kernel.org/r/20240611-asoc_next-v3-1-fcfd84b12164@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/sound/dmaengine_pcm.h | 1 +
sound/core/pcm_dmaengine.c | 10 ++++++++++
sound/soc/soc-generic-dmaengine-pcm.c | 8 ++++++++
3 files changed, 19 insertions(+)
diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
index 8c5e38180fb0..618405da95b3 100644
--- a/include/sound/dmaengine_pcm.h
+++ b/include/sound/dmaengine_pcm.h
@@ -34,6 +34,7 @@ snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream
int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
struct dma_chan *chan);
int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
+int snd_dmaengine_pcm_sync_stop(struct snd_pcm_substream *substream);
int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
dma_filter_fn filter_fn, void *filter_data);
diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c
index be58505889a3..db2229445256 100644
--- a/sound/core/pcm_dmaengine.c
+++ b/sound/core/pcm_dmaengine.c
@@ -342,6 +342,16 @@ int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
+int snd_dmaengine_pcm_sync_stop(struct snd_pcm_substream *substream)
+{
+ struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+
+ dmaengine_synchronize(prtd->dma_chan);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_sync_stop);
+
/**
* snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
* @substream: PCM substream
diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
index 9ef80a48707e..d65dc1acff43 100644
--- a/sound/soc/soc-generic-dmaengine-pcm.c
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -326,6 +326,12 @@ static int dmaengine_copy_user(struct snd_soc_component *component,
return 0;
}
+static int dmaengine_pcm_sync_stop(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream)
+{
+ return snd_dmaengine_pcm_sync_stop(substream);
+}
+
static const struct snd_soc_component_driver dmaengine_pcm_component = {
.name = SND_DMAENGINE_PCM_DRV_NAME,
.probe_order = SND_SOC_COMP_ORDER_LATE,
@@ -335,6 +341,7 @@ static const struct snd_soc_component_driver dmaengine_pcm_component = {
.trigger = dmaengine_pcm_trigger,
.pointer = dmaengine_pcm_pointer,
.pcm_construct = dmaengine_pcm_new,
+ .sync_stop = dmaengine_pcm_sync_stop,
};
static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
@@ -347,6 +354,7 @@ static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
.pointer = dmaengine_pcm_pointer,
.copy_user = dmaengine_copy_user,
.pcm_construct = dmaengine_pcm_new,
+ .sync_stop = dmaengine_pcm_sync_stop,
};
static const char * const dmaengine_pcm_dma_channel_names[] = {