Re: [PATCH v2] ASoC: qcom: Fix for DMA interrupt clear reg overwriting

[Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>]

On 05/06/2021 12:38, 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@xxxxxxxxxxxxxx>
> ---
>   sound/soc/qcom/lpass-platform.c | 17 +++++++++++------
>   1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/sound/soc/qcom/lpass-platform.c b/sound/soc/qcom/lpass-platform.c
> index 0df9481ea4c6..f220a2739ac3 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;
> @@ -650,7 +650,7 @@ 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, val_clr, val_mask;

minor nit here, variable name val_clr is pretty confusing to readers, It 
might be okay for irq clr register but we are using the same name of 
writing to other registers. So can I suggest you to reuse val variable.

other thing is val_mask, please rename this to mask and just set it in 
the start of function so you can avoid 3 extra lines below.

Other than that patch looks good to me!

--srini
>   	struct regmap *map;
>   	unsigned int dai_id = cpu_dai->driver->id;
>   
> @@ -676,8 +676,9 @@ 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);
> +		val_clr = LPAIF_IRQ_PER(chan) | val;
> +		val_mask = LPAIF_IRQ_ALL(chan);
> +		rv = regmap_update_bits(map, reg, val_mask, val_clr);
>   		if (rv) {
>   			dev_err(soc_runtime->dev,
>   				"error writing to irqclear reg: %d\n", rv);
> @@ -688,7 +689,9 @@ static irqreturn_t lpass_dma_interrupt_handler(
>   	}
>   
>   	if (interrupts & LPAIF_IRQ_XRUN(chan)) {
> -		rv = regmap_write(map, reg, LPAIF_IRQ_XRUN(chan) | val);
> +		val_clr = (LPAIF_IRQ_XRUN(chan) | val);
> +		val_mask = LPAIF_IRQ_ALL(chan);
> +		rv = regmap_update_bits(map, reg, val_mask, val_clr);
>   		if (rv) {
>   			dev_err(soc_runtime->dev,
>   				"error writing to irqclear reg: %d\n", rv);
> @@ -700,7 +703,9 @@ static irqreturn_t lpass_dma_interrupt_handler(
>   	}
>   
>   	if (interrupts & LPAIF_IRQ_ERR(chan)) {
> -		rv = regmap_write(map, reg, LPAIF_IRQ_ERR(chan) | val);
> +		val_clr = (LPAIF_IRQ_ERR(chan) | val);
> +		val_mask = LPAIF_IRQ_ALL(chan);
> +		rv = regmap_update_bits(map, reg, val_mask, val_clr);
>   		if (rv) {
>   			dev_err(soc_runtime->dev,
>   				"error writing to irqclear reg: %d\n", rv);