[PATCH v3] ASoC: amd: acp: Initialize list to store acp_stream during pcm_open

[PATCH v3] ASoC: amd: acp: Initialize list to store acp_stream during pcm_open

[Venkata Prasad Potturu]

From: Ajit Kumar Pandey <AjitKumar.Pandey@amd.com>

We are currently allocating acp_stream during pcm_open and saving
it in static array corresponds to array index calculated based on
cpu dai->driver id. This approach will fail if we have single dai
linked to multiple pcm device as we will have same dai->driver id
or array index for multiple pcm open. Initialize new linked list
stream_list to store opened pcm stream info dynamically.

Signed-off-by: Ajit Kumar Pandey <AjitKumar.Pandey@amd.com>
Signed-off-by: Venkata Prasad Potturu <venkataprasad.potturu@amd.com>
Reviewed-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
---
Changes since v2:
    -- Add locking mechanism in irq handler, linked list updatation and deletion.
Changes since v1:
    -- Fix compile error and remove unused variable.

 sound/soc/amd/acp/acp-platform.c | 43 ++++++++++++++++----------------
 sound/soc/amd/acp/amd.h          |  4 ++-
 2 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/sound/soc/amd/acp/acp-platform.c b/sound/soc/amd/acp/acp-platform.c
index f561d39b33e2..4d35c75611d3 100644
--- a/sound/soc/amd/acp/acp-platform.c
+++ b/sound/soc/amd/acp/acp-platform.c
@@ -93,8 +93,9 @@ static irqreturn_t i2s_irq_handler(int irq, void *data)
 	struct acp_dev_data *adata = data;
 	struct acp_resource *rsrc = adata->rsrc;
 	struct acp_stream *stream;
+	unsigned long flags;
 	u16 i2s_flag = 0;
-	u32 ext_intr_stat, ext_intr_stat1, i;
+	u32 ext_intr_stat, ext_intr_stat1;
 
 	if (!adata)
 		return IRQ_NONE;
@@ -104,14 +105,13 @@ static irqreturn_t i2s_irq_handler(int irq, void *data)
 
 	ext_intr_stat = readl(ACP_EXTERNAL_INTR_STAT(adata, rsrc->irqp_used));
 
-	for (i = 0; i < ACP_MAX_STREAM; i++) {
-		stream = adata->stream[i];
+	spin_lock_irqsave(&adata->acp_lock, flags);
+	list_for_each_entry(stream, &adata->stream_list, list) {
 		if (stream && (ext_intr_stat & stream->irq_bit)) {
 			writel(stream->irq_bit,
 			       ACP_EXTERNAL_INTR_STAT(adata, rsrc->irqp_used));
 			snd_pcm_period_elapsed(stream->substream);
 			i2s_flag = 1;
-			break;
 		}
 		if (adata->rsrc->no_of_ctrls == 2) {
 			if (stream && (ext_intr_stat1 & stream->irq_bit)) {
@@ -119,10 +119,10 @@ static irqreturn_t i2s_irq_handler(int irq, void *data)
 				       (rsrc->irqp_used - 1)));
 				snd_pcm_period_elapsed(stream->substream);
 				i2s_flag = 1;
-				break;
 			}
 		}
 	}
+	spin_unlock_irqrestore(&adata->acp_lock, flags);
 	if (i2s_flag)
 		return IRQ_HANDLED;
 
@@ -146,9 +146,8 @@ static void config_pte_for_stream(struct acp_dev_data *adata, struct acp_stream
 	writel(0x01, adata->acp_base + ACPAXI2AXI_ATU_CTRL);
 }
 
-static void config_acp_dma(struct acp_dev_data *adata, int cpu_id, int size)
+static void config_acp_dma(struct acp_dev_data *adata, struct acp_stream *stream, int size)
 {
-	struct acp_stream *stream = adata->stream[cpu_id];
 	struct snd_pcm_substream *substream = stream->substream;
 	struct acp_resource *rsrc = adata->rsrc;
 	dma_addr_t addr = substream->dma_buffer.addr;
@@ -174,21 +173,22 @@ static void config_acp_dma(struct acp_dev_data *adata, int cpu_id, int size)
 
 static int acp_dma_open(struct snd_soc_component *component, struct snd_pcm_substream *substream)
 {
-	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
-	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(soc_runtime, 0);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct device *dev = component->dev;
 	struct acp_dev_data *adata = dev_get_drvdata(dev);
 	struct acp_stream *stream;
-	int stream_id = cpu_dai->driver->id * 2 + substream->stream;
 	int ret;
+	unsigned long flags;
 
 	stream = kzalloc(sizeof(*stream), GFP_KERNEL);
 	if (!stream)
 		return -ENOMEM;
 
 	stream->substream = substream;
-	adata->stream[stream_id] = stream;
+
+	spin_lock_irqsave(&adata->acp_lock, flags);
+	list_add_tail(&stream->list, &adata->stream_list);
+	spin_unlock_irqrestore(&adata->acp_lock, flags);
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		runtime->hw = acp_pcm_hardware_playback;
@@ -212,16 +212,13 @@ static int acp_dma_hw_params(struct snd_soc_component *component,
 			     struct snd_pcm_substream *substream,
 			     struct snd_pcm_hw_params *params)
 {
-	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
 	struct acp_dev_data *adata = snd_soc_component_get_drvdata(component);
-	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(soc_runtime, 0);
 	struct acp_stream *stream = substream->runtime->private_data;
-	int stream_id = cpu_dai->driver->id * 2 + substream->stream;
 	u64 size = params_buffer_bytes(params);
 
 	/* Configure ACP DMA block with params */
 	config_pte_for_stream(adata, stream);
-	config_acp_dma(adata, stream_id, size);
+	config_acp_dma(adata, stream, size);
 
 	return 0;
 }
@@ -261,16 +258,16 @@ static int acp_dma_new(struct snd_soc_component *component,
 static int acp_dma_close(struct snd_soc_component *component,
 			 struct snd_pcm_substream *substream)
 {
-	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
-	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(soc_runtime, 0);
 	struct device *dev = component->dev;
 	struct acp_dev_data *adata = dev_get_drvdata(dev);
-	struct acp_stream *stream;
-	int stream_id = cpu_dai->driver->id * 2 + substream->stream;
+	struct acp_stream *stream = substream->runtime->private_data;
+	unsigned long flags;
 
-	stream = adata->stream[stream_id];
+	/* Remove entry from list */
+	spin_lock_irqsave(&adata->acp_lock, flags);
+	list_del(&stream->list);
+	spin_unlock_irqrestore(&adata->acp_lock, flags);
 	kfree(stream);
-	adata->stream[stream_id] = NULL;
 
 	return 0;
 }
@@ -305,6 +302,10 @@ int acp_platform_register(struct device *dev)
 		dev_err(dev, "Fail to register acp i2s component\n");
 		return status;
 	}
+
+	INIT_LIST_HEAD(&adata->stream_list);
+	spin_lock_init(&adata->acp_lock);
+
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(acp_platform_register, SND_SOC_ACP_COMMON);
diff --git a/sound/soc/amd/acp/amd.h b/sound/soc/amd/acp/amd.h
index 60a7c95f134f..be8bb8247c4e 100644
--- a/sound/soc/amd/acp/amd.h
+++ b/sound/soc/amd/acp/amd.h
@@ -91,6 +91,7 @@ struct acp_chip_info {
 };
 
 struct acp_stream {
+	struct list_head list;
 	struct snd_pcm_substream *substream;
 	int irq_bit;
 	int dai_id;
@@ -123,7 +124,8 @@ struct acp_dev_data {
 	struct snd_soc_dai_driver *dai_driver;
 	int num_dai;
 
-	struct acp_stream *stream[ACP_MAX_STREAM];
+	struct list_head stream_list;
+	spinlock_t acp_lock;
 
 	struct snd_soc_acpi_mach *machines;
 	struct platform_device *mach_dev;
-- 
2.25.1

Re: [PATCH v3] ASoC: amd: acp: Initialize list to store acp_stream during pcm_open

[Mark Brown]

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On Thu, Jul 28, 2022 at 06:10:50PM +0530, Venkata Prasad Potturu wrote:

> @@ -104,14 +105,13 @@ static irqreturn_t i2s_irq_handler(int irq, void *data)
>  
>  	ext_intr_stat = readl(ACP_EXTERNAL_INTR_STAT(adata, rsrc->irqp_used));
>  
> -	for (i = 0; i < ACP_MAX_STREAM; i++) {
> -		stream = adata->stream[i];
> +	spin_lock_irqsave(&adata->acp_lock, flags);
> +	list_for_each_entry(stream, &adata->stream_list, list) {

If we're already in an interrupt handler here (presumably not a threaded
one) why are we using irqsave?

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Re: [PATCH v3] ASoC: amd: acp: Initialize list to store acp_stream during pcm_open

[Takashi Iwai]

On Fri, 29 Jul 2022 12:34:51 +0200,
Venkata Prasad Potturu wrote:
> 
> 
> On 7/28/22 18:19, Mark Brown wrote:
> Thanks for your time.
> 
>     On Thu, Jul 28, 2022 at 06:10:50PM +0530, Venkata Prasad Potturu wrote:
> 
>         @@ -104,14 +105,13 @@ static irqreturn_t i2s_irq_handler(int irq, void *data)
>          
>               ext_intr_stat = readl(ACP_EXTERNAL_INTR_STAT(adata, rsrc->irqp_used));
>          
>         -     for (i = 0; i < ACP_MAX_STREAM; i++) {
>         -                           stream = adata->stream[i];
>         +     spin_lock_irqsave(&adata->acp_lock, flags);
>         +     list_for_each_entry(stream, &adata->stream_list, list) {
>         
>     If we're already in an interrupt handler here (presumably not a threaded
>     one) why are we using irqsave?
>     
> Yes, your statement make sense, I have followed below statement in kernel
> document. so used irqsave in interrupt context as well.
> 
> We will change it to spin_lock() and send it in the next version.
> 
> statement:- spin_lock_irqsave() will turn off interrupts if they are on,
> otherwise does nothing (if we are already in an interrupt handler), hence
> these functions are safe to call from any context.

Also the open and close callbacks are certainly non-irq context, hence
you can use spin_lock_irq() instead of irqsave(), too.


Takashi

Re: [PATCH v3] ASoC: amd: acp: Initialize list to store acp_stream during pcm_open

[Venkata Prasad Potturu]

On 7/29/22 16:19, Takashi Iwai wrote:
Thanks for your time.
> [CAUTION: External Email]
>
> On Fri, 29 Jul 2022 12:34:51 +0200,
> Venkata Prasad Potturu wrote:
>>
>> On 7/28/22 18:19, Mark Brown wrote:
>> Thanks for your time.
>>
>>      On Thu, Jul 28, 2022 at 06:10:50PM +0530, Venkata Prasad Potturu wrote:
>>
>>          @@ -104,14 +105,13 @@ static irqreturn_t i2s_irq_handler(int irq, void *data)
>>
>>                ext_intr_stat = readl(ACP_EXTERNAL_INTR_STAT(adata, rsrc->irqp_used));
>>
>>          -     for (i = 0; i < ACP_MAX_STREAM; i++) {
>>          -                           stream = adata->stream[i];
>>          +     spin_lock_irqsave(&adata->acp_lock, flags);
>>          +     list_for_each_entry(stream, &adata->stream_list, list) {
>>
>>      If we're already in an interrupt handler here (presumably not a threaded
>>      one) why are we using irqsave?
>>
>> Yes, your statement make sense, I have followed below statement in kernel
>> document. so used irqsave in interrupt context as well.
>>
>> We will change it to spin_lock() and send it in the next version.
>>
>> statement:- spin_lock_irqsave() will turn off interrupts if they are on,
>> otherwise does nothing (if we are already in an interrupt handler), hence
>> these functions are safe to call from any context.
> Also the open and close callbacks are certainly non-irq context, hence
> you can use spin_lock_irq() instead of irqsave(), too.

Okay. Thanks for your suggestion.

We will use accordingly.

>
>
> Takashi