[PATCH 3/3] ASoC: qcom: q6apm: Unmap DSP buffers before removing the topology

[Shawn Guo]

Since buffers are mapped once in pcm_new() and unmapped in pcm_free(),
the unmap relies on the graph info still being registered. During card
teardown, however, soc_cleanup_card_resources() removes the components
before it frees the PCM runtimes. q6apm-audio's remove callback unloads
the topology, which frees every audioreach_graph_info, so by the time
q6apm_dai_pcm_free() runs the idr lookup fails and the unmap silently
returns -ENODEV. The DSP keeps the old mapping.

When the card is bound again, for example after unbinding and binding
any codec on it, pcm_new() maps the same buffer once more, the DSP
rejects it and the front-end PCM is not created:

  qcom-apm gprsvc:service:2:1: Error (1) Processing 0x0100100c cmd
  qcom-apm gprsvc:service:2:1: DSP returned error[100100c] 1
  q6apm-dai ...: Audio Start: Buffer Allocation failed rc = -22
  snd-sc8280xp sound: ASoC: can't create pcm MultiMedia1 Playback :-22

Release the circular and position buffer mappings of all graphs in
q6apm_audio_remove() while the graph info still exists. The unmap
helper now takes the q6apm instance directly, since it is called from
the APM component rather than from a q6apm-dai child device.

Fixes: 8ea6e25c8536 ("ASoC: qcom: q6apm: Add support for early buffer mapping on DSP")
Assisted-by: LLM
Signed-off-by: Shawn Guo <shengchao.guo@xxxxxxxxxxxxxxxx>
---
 sound/soc/qcom/qdsp6/q6apm.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6apm.c b/sound/soc/qcom/qdsp6/q6apm.c
index 72ccaea1feb3..bfbcf259002e 100644
--- a/sound/soc/qcom/qdsp6/q6apm.c
+++ b/sound/soc/qcom/qdsp6/q6apm.c
@@ -321,11 +321,10 @@ int q6apm_alloc_fragments(struct q6apm_graph *graph, unsigned int dir, phys_addr
 }
 EXPORT_SYMBOL_GPL(q6apm_alloc_fragments);
 
-static int __q6apm_unmap_memory_fixed_region(struct device *dev, unsigned int graph_id,
+static int __q6apm_unmap_memory_fixed_region(struct q6apm *apm, unsigned int graph_id,
 					     bool is_pos_buf)
 {
 	struct apm_cmd_shared_mem_unmap_regions *cmd;
-	struct q6apm *apm = dev_get_drvdata(dev->parent);
 	struct audioreach_graph_info *info;
 	uint32_t mem_map_handle;
 	uint32_t pos_mask = is_pos_buf ? APM_MMAP_TOKEN_MAP_TYPE_POS_BUF : 0;
@@ -357,13 +356,15 @@ static int __q6apm_unmap_memory_fixed_region(struct device *dev, unsigned int gr
 
 int q6apm_unmap_memory_fixed_region(struct device *dev, unsigned int graph_id)
 {
-	return __q6apm_unmap_memory_fixed_region(dev, graph_id, false);
+	return __q6apm_unmap_memory_fixed_region(dev_get_drvdata(dev->parent),
+						 graph_id, false);
 }
 EXPORT_SYMBOL_GPL(q6apm_unmap_memory_fixed_region);
 
 int q6apm_unmap_pos_buffer(struct device *dev, unsigned int graph_id)
 {
-	return __q6apm_unmap_memory_fixed_region(dev, graph_id, true);
+	return __q6apm_unmap_memory_fixed_region(dev_get_drvdata(dev->parent),
+						 graph_id, true);
 }
 EXPORT_SYMBOL_GPL(q6apm_unmap_pos_buffer);
 
@@ -850,6 +851,21 @@ static int q6apm_audio_probe(struct snd_soc_component *component)
 
 static void q6apm_audio_remove(struct snd_soc_component *component)
 {
+	struct q6apm *apm = dev_get_drvdata(component->dev);
+	struct audioreach_graph_info *info;
+	int id;
+
+	/*
+	 * The card core removes components before freeing the PCMs, so
+	 * q6apm-dai's pcm_free() runs after the topology (and graph_info)
+	 * is gone and can no longer unmap. Release the DSP mappings here,
+	 * otherwise the next pcm_new() fails to map the same buffer again.
+	 */
+	idr_for_each_entry(&apm->graph_info_idr, info, id) {
+		__q6apm_unmap_memory_fixed_region(apm, id, false);
+		__q6apm_unmap_memory_fixed_region(apm, id, true);
+	}
+
 	/* remove topology */
 	snd_soc_tplg_component_remove(component);
 }
-- 
2.43.0