Re: [PATCH 2/2] ALSA: pcmtest: Don't use static storage to track per device data

[Ivan Orlov <ivan.orlov0322@gmail.com>]

On 7/7/23 11:50, Uwe Kleine-König wrote:
> While there is probably only ever a single instance of such a pcmtst
> device, it's still bad style to use a static variable to store per
> device data. Make use of platform_get_drvdata() and
> platform_set_drvdata() which fixes a data corruption if there should be
> two or more such devices (or this driver is used as a template for
> another driver).
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>   sound/drivers/pcmtest.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c
> index 1fff85feaf82..291e7fe47893 100644
> --- a/sound/drivers/pcmtest.c
> +++ b/sound/drivers/pcmtest.c
> @@ -110,8 +110,6 @@ struct pcmtst_buf_iter {
>   	struct timer_list timer_instance;
>   };
>   
> -static struct pcmtst *pcmtst;
> -
>   static struct snd_pcm_hardware snd_pcmtst_hw = {
>   	.info = (SNDRV_PCM_INFO_INTERLEAVED |
>   		 SNDRV_PCM_INFO_BLOCK_TRANSFER |
> @@ -552,6 +550,7 @@ static int snd_pcmtst_create(struct snd_card *card, struct platform_device *pdev
>   static int pcmtst_probe(struct platform_device *pdev)
>   {
>   	struct snd_card *card;
> +	struct pcmtst *pcmtst;
>   	int err;
>   
>   	err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> @@ -573,11 +572,15 @@ static int pcmtst_probe(struct platform_device *pdev)
>   	if (err < 0)
>   		return err;
>   
> +	platform_set_drvdata(pdev, pcmtst);
> +
>   	return 0;
>   }
>   
> -static void pdev_remove(struct platform_device *dev)
> +static void pdev_remove(struct platform_device *pdev)
>   {
> +	struct pcmtst *pcmtst = platform_get_drvdata(pdev);
> +
>   	snd_pcmtst_free(pcmtst);
>   }
>   

Also looks good.

Acked-by: Ivan Orlov <ivan.orlov0322@gmail.com>