Subject: Re: [PATCH] media: nxp: imx8-isi: remove kzalloc_objs

From: Laurent Pinchart <[email-masked]>
Date: Fri, 20 Mar 2026 00:09:01 +0200

On Thu, Mar 05, 2026 at 08:45:36PM -0800, Rosen Penev wrote:
> Use a flexible arraay member to combine allocations.
> 
> It looks like pipes never gets freed anywhere. Meaning this effectively
> fixes a memory leak.
> 
> Signed-off-by: Rosen Penev <[email-masked]>
> ---
>  drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c | 11 ++++-------
>  drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h |  3 ++-
>  2 files changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c
> index 16392420903a..657ffecc4d7e 100644
> --- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c
> +++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c
> @@ -459,25 +459,21 @@ static const struct dev_pm_ops mxc_isi_pm_ops = {
>  
>  static int mxc_isi_probe(struct platform_device *pdev)
>  {
> +	const struct mxc_isi_plat_data *pdata;
>  	struct device *dev = &pdev->dev;
>  	struct mxc_isi_dev *isi;
>  	unsigned int dma_size;
>  	unsigned int i;
>  	int ret = 0;
>  
> -	isi = devm_kzalloc(dev, sizeof(*isi), GFP_KERNEL);
> +	pdata = of_device_get_match_data(dev);
> +	isi = devm_kzalloc(dev, struct_size(isi, pipes, pdata->num_channels), GFP_KERNEL);
>  	if (!isi)
>  		return -ENOMEM;
>  
>  	isi->dev = dev;
>  	platform_set_drvdata(pdev, isi);
>  
> -	isi->pdata = of_device_get_match_data(dev);

I'd keep

	isi->pdata = pdata;

here and not below.

> -
> -	isi->pipes = kzalloc_objs(isi->pipes[0], isi->pdata->num_channels);

Wouldn't it be simpler to just replace this with devm_kcalloc() ?

	isi->pipes = devm_kcalloc(dev, isi->pdata->num_channels,
				  sizeof(isi->pipes[0]), GFP_KERNEL);

No other change would be needed.

> -	if (!isi->pipes)
> -		return -ENOMEM;
> -
>  	isi->num_clks = devm_clk_bulk_get_all(dev, &isi->clks);
>  	if (isi->num_clks < 0)
>  		return dev_err_probe(dev, isi->num_clks, "Failed to get clocks\n");
> @@ -487,6 +483,7 @@ static int mxc_isi_probe(struct platform_device *pdev)
>  		return dev_err_probe(dev, PTR_ERR(isi->regs),
>  				     "Failed to get ISI register map\n");
>  
> +	isi->pdata = pdata;
>  	if (isi->pdata->gasket_ops) {
>  		isi->gasket = syscon_regmap_lookup_by_phandle(dev->of_node,
>  							      "fsl,blk-ctrl");
> diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
> index 3cbd35305af0..99532efa4e41 100644
> --- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
> +++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-core.h
> @@ -286,7 +286,6 @@ struct mxc_isi_dev {
>  	struct regmap			*gasket;
>  
>  	struct mxc_isi_crossbar		crossbar;
> -	struct mxc_isi_pipe		*pipes;
>  	struct mxc_isi_m2m		m2m;
>  
>  	struct media_device		media_dev;
> @@ -294,6 +293,8 @@ struct mxc_isi_dev {
>  	struct v4l2_async_notifier	notifier;
>  
>  	struct dentry			*debugfs_root;
> +
> +	struct mxc_isi_pipe		pipes[];
>  };
>  
>  extern const struct mxc_gasket_ops mxc_imx8_gasket_ops;

-- 
Regards,

Laurent Pinchart