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

[Stephen Boyd]

Quoting Srinivasa Rao Mandadapu (2021-06-02 22:05:30)
> This patch fixes the DMA interrupt registers overwriting

 $ git grep "This patch" -- Documentation/process

> issue in lpass platform interrupt handler.

Can you describe the issue more?

>
> Signed-off-by: Srinivasa Rao Mandadapu <srivasam@xxxxxxxxxxxxxx>
> ---

Any Fixes tag?

>  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..e02caa121fa4 100644
> --- a/sound/soc/qcom/lpass-platform.c
> +++ b/sound/soc/qcom/lpass-platform.c
> @@ -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 = 0, val = 0, val_clr = 0, val_mask = 0;

Why assign to 0 and then overwrite it?

>         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);

Is the extra parenthesis useful?

> +               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);