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

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: Srinivasa Rao Mandadapu <srivasam@codeaurora.org>,
	agross@kernel.org, bjorn.andersson@linaro.org,
	lgirdwood@gmail.com, broonie@kernel.org, robh+dt@kernel.org,
	plai@codeaurora.org, bgoswami@codeaurora.org, perex@perex.cz,
	tiwai@suse.com, rohitkr@codeaurora.org,
	linux-arm-msm@vger.kernel.org, alsa-devel@alsa-project.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	swboyd@chromium.org, judyhsiao@chromium.org
Subject: Re: [PATCH v2] ASoC: qcom: Fix for DMA interrupt clear reg overwriting
Date: Mon, 7 Jun 2021 15:50:12 +0100	[thread overview]
Message-ID: <ac3e70da-7d82-2021-3a25-08179aeb6b54@linaro.org> (raw)
In-Reply-To: <20210605113809.26584-1-srivasam@codeaurora.org>

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@codeaurora.org>
> ---
>   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);
> 