Re: [PATCH v3] ASoC: qcom: Fix for DMA interrupt clear reg overwriting

[Srinivas Kandagatla <srinivas.kandagatla@linaro.org>]

Hi Marek/Srinivasa,


On 17/06/2021 20:35, Marek Szyprowski wrote:
> Hi,
> 
> On 09.06.2021 09:23, Srinivasa Rao Mandadapu wrote:
>> The DMA interrupt clear register overwritten during
>> simultaneous playback and capture in lpass platform
>> interrupt handler. It's causing playback or capture stuck
>> in similtaneous plaback on speaker and capture on dmic test.
>> Update appropriate reg fields of corresponding channel instead
>> of entire register write.
>>
>> Fixes: commit c5c8635a04711 ("ASoC: qcom: Add LPASS platform driver")
>>
>> Signed-off-by: Srinivasa Rao Mandadapu <srivasam@codeaurora.org>
> 
Can you please try this patch and let us know if this fixes the issue

------------------------->cut<-------------------------------
Author: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Date:   Mon Jun 21 12:38:43 2021 +0100

     ASoC: qcom: lpass-cpu: mark IRQ_CLEAR register as volatile and readable

     Currently IRQ_CLEAR register is marked as write-only, however using
     regmap_update_bits on this register will have some side effects.
     so mark IRQ_CLEAR register appropriately as readable and volatile.

     Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

diff --git a/sound/soc/qcom/lpass-cpu.c b/sound/soc/qcom/lpass-cpu.c
index 0b9cbf2ce505..8998697cd1e1 100644
--- a/sound/soc/qcom/lpass-cpu.c
+++ b/sound/soc/qcom/lpass-cpu.c
@@ -525,6 +525,8 @@ static bool lpass_cpu_regmap_readable(struct device 
*dev, unsigned int reg)
                         return true;

         for (i = 0; i < v->irq_ports; ++i) {
+               if (reg == LPAIF_IRQCLEAR_REG(v, i))
+                       return true;
                 if (reg == LPAIF_IRQEN_REG(v, i))
                         return true;
                 if (reg == LPAIF_IRQSTAT_REG(v, i))
@@ -566,9 +568,12 @@ static bool lpass_cpu_regmap_volatile(struct device 
*dev, unsigned int reg)
         struct lpass_variant *v = drvdata->variant;
         int i;

-       for (i = 0; i < v->irq_ports; ++i)
+       for (i = 0; i < v->irq_ports; ++i) {
+               if (reg == LPAIF_IRQCLEAR_REG(v, i))
+                       return true;
                 if (reg == LPAIF_IRQSTAT_REG(v, i))
                         return true;
+       }

         for (i = 0; i < v->rdma_channels; ++i)
                 if (reg == LPAIF_RDMACURR_REG(v, i))

------------------------->cut<-------------------------------

--srini

> This patch landed recently in linux-next as commit da0363f7bfd3 ("ASoC:
> qcom: Fix for DMA interrupt clear reg overwriting"). It breaks ALSA
> playback on DragonBoard 410c (arch/arm64/boot/dts/qcom/apq8016-sbc.dts).
> After applying this patch, running 'speaker-test -l1' never finishes.
> There is no error nor kernel warning message. Before that commit, the
> playback worked fine on that board.
> 
>> ---
>> Changes since v2:
>> 	-- Removed redundant variables.
>> Changes since v1:
>> 	-- Subject lines changed.
>>    sound/soc/qcom/lpass-platform.c | 12 ++++++------
>>    1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/sound/soc/qcom/lpass-platform.c b/sound/soc/qcom/lpass-platform.c
>> index 0df9481ea4c6..f9df76d37858 100644
>> --- a/sound/soc/qcom/lpass-platform.c
>> +++ b/sound/soc/qcom/lpass-platform.c
>> @@ -526,7 +526,7 @@ static int lpass_platform_pcmops_trigger(struct snd_soc_component *component,
>>    			return -EINVAL;
>>    		}
>>    
>> -		ret = regmap_write(map, reg_irqclr, val_irqclr);
>> +		ret = regmap_update_bits(map, reg_irqclr, val_irqclr, val_irqclr);
>>    		if (ret) {
>>    			dev_err(soc_runtime->dev, "error writing to irqclear reg: %d\n", ret);
>>    			return ret;
>> @@ -650,10 +650,11 @@ static irqreturn_t lpass_dma_interrupt_handler(
>>    	struct lpass_variant *v = drvdata->variant;
>>    	irqreturn_t ret = IRQ_NONE;
>>    	int rv;
>> -	unsigned int reg = 0, val = 0;
>> +	unsigned int reg, val, mask;
>>    	struct regmap *map;
>>    	unsigned int dai_id = cpu_dai->driver->id;
>>    
>> +	mask = LPAIF_IRQ_ALL(chan);
>>    	switch (dai_id) {
>>    	case LPASS_DP_RX:
>>    		map = drvdata->hdmiif_map;
>> @@ -676,8 +677,7 @@ static irqreturn_t lpass_dma_interrupt_handler(
>>    	return -EINVAL;
>>    	}
>>    	if (interrupts & LPAIF_IRQ_PER(chan)) {
>> -
>> -		rv = regmap_write(map, reg, LPAIF_IRQ_PER(chan) | val);
>> +		rv = regmap_update_bits(map, reg, mask, (LPAIF_IRQ_PER(chan) | val));
>>    		if (rv) {
>>    			dev_err(soc_runtime->dev,
>>    				"error writing to irqclear reg: %d\n", rv);
>> @@ -688,7 +688,7 @@ static irqreturn_t lpass_dma_interrupt_handler(
>>    	}
>>    
>>    	if (interrupts & LPAIF_IRQ_XRUN(chan)) {
>> -		rv = regmap_write(map, reg, LPAIF_IRQ_XRUN(chan) | val);
>> +		rv = regmap_update_bits(map, reg, mask, (LPAIF_IRQ_XRUN(chan) | val));
>>    		if (rv) {
>>    			dev_err(soc_runtime->dev,
>>    				"error writing to irqclear reg: %d\n", rv);
>> @@ -700,7 +700,7 @@ static irqreturn_t lpass_dma_interrupt_handler(
>>    	}
>>    
>>    	if (interrupts & LPAIF_IRQ_ERR(chan)) {
>> -		rv = regmap_write(map, reg, LPAIF_IRQ_ERR(chan) | val);
>> +		rv = regmap_update_bits(map, reg, mask, (LPAIF_IRQ_ERR(chan) | val));
>>    		if (rv) {
>>    			dev_err(soc_runtime->dev,
>>    				"error writing to irqclear reg: %d\n", rv);
> 
> Best regards
>