Re: [PATCH] serial: hvc: use modern IRQ acquisition API

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] tty: hvc: permanent probe failure on -EPROBE_DEFER due to state corruption
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commit 3ec0d2af78ba8c496b4a45223b1fb5f9769284c2
Author: Rosen Penev <rosenp@gmail.com>

serial: hvc: use modern IRQ acquisition API

This patch updates the hvc_opal driver to use platform_get_irq_optional()
for acquiring its interrupt. It adds handling for -EPROBE_DEFER and other
negative error codes returned by the new API.

> diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
> index 402da9e7c5346..ce726b8b5ab00 100644
> --- a/drivers/tty/hvc/hvc_opal.c
> +++ b/drivers/tty/hvc/hvc_opal.c
[ ... ]
> @@ -209,8 +209,10 @@ static int hvc_opal_probe(struct platform_device *dev)
>  		dev->dev.of_node,
>  		boot ? " (boot console)" : "");
>  
> -	irq = irq_of_parse_and_map(dev->dev.of_node, 0);
> -	if (!irq) {
> +	irq = platform_get_irq_optional(dev, 0);
> +	if (irq == -EPROBE_DEFER)
> +		return irq;

[Severity: High]
Can this early return cause a memory leak and permanent probe failure on retry?

Earlier in hvc_opal_probe(), the driver allocates a struct hvc_opal_priv and
saves it in a global array:

drivers/tty/hvc/hvc_opal.c:hvc_opal_probe() {
    ...
    } else if (hvc_opal_privs[termno] == NULL) {
        pv = kzalloc_obj(struct hvc_opal_priv);
        if (!pv)
            return -ENOMEM;
        pv->proto = proto;
        hvc_opal_privs[termno] = pv;
    ...
}

If platform_get_irq_optional() returns -EPROBE_DEFER here, the function
returns immediately without freeing pv or clearing hvc_opal_privs[termno].

When the driver is later re-probed, it will see that hvc_opal_privs[termno]
is no longer NULL and fail with -ENXIO:

drivers/tty/hvc/hvc_opal.c:hvc_opal_probe() {
    ...
    } else {
        pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n",
               dev->dev.of_node, termno);
        return -ENXIO;
    }
}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260925185011.61259-1-rosenp@gmail.com?part=1