Re: [PATCH v2 2/2] memory: ti-k3-fsas: Add TI FSS_FSAS driver

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Critical] Missing PM Runtime integration causes bus faults and silent state loss.
- [Critical] Lack of probe ordering guarantees between the FSAS wrapper and the OSPI driver risks DMA corruption.
--

commit d3b703966890d77f64fc1cc0139d8a00699e6a78
Author: Santhosh Kumar K <s-k6@ti.com>

memory: ti-k3-fsas: Add TI FSS_FSAS driver

This patch adds a platform driver for the TI Flash SubSystem Application
Subsystem in K3 SoCs. It configures the SYSCONFIG register to disable OSPI
XIP prefetch, preventing DMA data corruption.

> diff --git a/drivers/memory/ti-k3-fsas.c b/drivers/memory/ti-k3-fsas.c
> new file mode 100644
> index 0000000000000..a5f42afc694c5
> --- /dev/null
> +++ b/drivers/memory/ti-k3-fsas.c
[ ... ]
> +static int k3_fsas_probe(struct platform_device *pdev)
> +{
> +	struct k3_fsas *fsas;
> +
> +	fsas = devm_kzalloc(&pdev->dev, sizeof(*fsas), GFP_KERNEL);
> +	if (!fsas)
> +		return -ENOMEM;
> +
> +	fsas->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(fsas->base))
> +		return PTR_ERR(fsas->base);
> +
> +	platform_set_drvdata(pdev, fsas);
> +
> +	k3_fsas_disable_xip_prefetch(fsas);

[Severity: Critical]
Is it possible for the device to be unpowered when accessing the registers
here? 

Accessing fsas->base without first calling pm_runtime_enable() and
pm_runtime_get_sync() could cause a synchronous external abort on K3 SoCs.

[Severity: Critical]
Is there anything guaranteeing this probe finishes before the main OSPI
controller probes?

If the OSPI driver (cadence-quadspi) probes and initiates DMA transfers
before this independent platform driver runs, the transfers could occur with
XIP prefetch enabled, corrupting the data.

> +
> +	return 0;
> +}
> +
> +static int k3_fsas_resume(struct device *dev)
> +{
> +	k3_fsas_disable_xip_prefetch(dev_get_drvdata(dev));
> +	return 0;
> +}
> +
> +static DEFINE_SIMPLE_DEV_PM_OPS(k3_fsas_pm_ops, NULL, k3_fsas_resume);

[Severity: Critical]
Will the hardware state be lost during runtime suspend?

By using DEFINE_SIMPLE_DEV_PM_OPS without runtime PM callbacks, if the
domain goes into runtime suspend (e.g. when the OSPI controller is idle),
the hardware state could reset. 

Because there are no runtime_resume callbacks, the FSAS_SYSCONFIG_DISXIP
bit will remain lost. The OSPI controller could then perform subsequent DMA
transfers with XIP prefetch enabled, causing silent data corruption.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260629072055.896322-1-s-k6@ti.com?part=2