Re: [RFC PATCH 03/11] media: iris: Add helper to create a context bank device

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The context bank platform device is registered with a hardcoded instance ID of 0 instead of `PLATFORM_DEVID_AUTO`, causing sysfs naming collisions and probe failures when multiple instances of the Iris core are present.
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--- Patch [3]: [RFC PATCH 03/11] media: iris: Add helper to create a context bank device ---
commit d34d83e19b25d09de0876c75096c26d30aa90223
Author: Vikash Garodia <vikash.garodia@oss.qualcomm.com>

media: iris: Add helper to create a context bank device

This commit adds a helper function to register a subnode from the device
tree as a separate platform device, allowing it to have its own IOMMU
context bank.

> diff --git a/drivers/media/platform/qcom/iris/iris_resources.c b/drivers/media/platform/qcom/iris/iris_resources.c
> --- a/drivers/media/platform/qcom/iris/iris_resources.c
> +++ b/drivers/media/platform/qcom/iris/iris_resources.c

[ ... ]

> +struct device *iris_create_cb_dev(struct iris_core *core, const char *name)
> +{
> +	struct platform_device_info plat_dev_info = {};
> +	struct device_node *child_of_node;
> +	struct platform_device *pdev;
> +
> +	child_of_node = of_get_child_by_name(core->dev->of_node, name);
> +	if (!child_of_node)
> +		return NULL;
> +
> +	plat_dev_info.dma_mask = core->iris_platform_data->dma_mask;
> +	plat_dev_info.fwnode = &child_of_node->fwnode;
> +	plat_dev_info.name = child_of_node->name;
> +	plat_dev_info.parent = core->dev;
> +
> +	pdev = platform_device_register_full(&plat_dev_info);

[Severity: Medium]
Does this code risk a sysfs naming collision if multiple Iris instances are
present?

Since plat_dev_info is zero-initialized, the device id defaults to 0 instead
of PLATFORM_DEVID_AUTO. If the SoC device tree specifies multiple Iris cores,
won't the second instance fail to register its context bank device due to a
sysfs naming collision in /sys/bus/platform/devices/ (for example, trying
to register a device named 'pixel.0' twice)?

> +	of_node_put(child_of_node);
> +	if (IS_ERR(pdev))
> +		return ERR_CAST(pdev);
> +
> +	return &pdev->dev;
> +}

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Sashiko AI review · https://sashiko.dev/#/patchset/20260709-vpu_iommu_iova_handling-v1-0-72bb62cb2dfd@oss.qualcomm.com?part=3