Re: [PATCH v8 7/8] usb: misc: qcom_eud: fix virtual attach/detach event handling

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [Medium] Disabling EUD while virtually detached leaves the USB controller stuck in a disconnected state.
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commit 29002e5f224d237570095828a981e93ede8860c1
Author: Elson Serrao <elson.serrao@oss.qualcomm.com>

usb: misc: qcom_eud: fix virtual attach/detach event handling

EUD provides virtual USB attach/detach events to simulate cable plug/unplug
while maintaining the physical debug connection. This commit fixes virtual
detach handling by setting the USB role to NONE instead of HOST.

> diff --git a/drivers/usb/misc/qcom_eud.c b/drivers/usb/misc/qcom_eud.c
> index 1ed81e0c7dc8e..423320cdc704a 100644
> --- a/drivers/usb/misc/qcom_eud.c
> +++ b/drivers/usb/misc/qcom_eud.c
> @@ -313,10 +313,26 @@ static irqreturn_t handle_eud_irq_thread(int irq, void *data)
>  	if (!chip->enabled || path->curr_role != USB_ROLE_DEVICE)
>  		goto out;
>  
> [ ... ]
>  	if (chip->usb_attached)
>  		ret = usb_role_switch_set_role(path->controller_sw, USB_ROLE_DEVICE);
>  	else
> -		ret = usb_role_switch_set_role(path->controller_sw, USB_ROLE_HOST);
> +		ret = usb_role_switch_set_role(path->controller_sw, USB_ROLE_NONE);

[Severity: Medium]
This is a pre-existing issue, but does disabling EUD while virtually detached
leave the USB controller stuck in a disconnected state?

If EUD is enabled via sysfs, a physical connection is made, EUD triggers a
virtual detach (setting the controller role to NONE), and a user disables
EUD via the enable sysfs node.

The driver disables EUD, but no role restoration is performed for
path->controller_sw to reflect the physical path->curr_role:

drivers/usb/misc/qcom_eud.c:enable_store() {
    ...
	} else {
		ret = disable_eud(chip);
		if (ret) {
			dev_err(chip->dev, "failed to disable eud\n");
			return ret;
		}
	}
    ...
}

Does the controller remain functionally disconnected (USB_ROLE_NONE) despite
being physically connected (USB_ROLE_DEVICE) until a physical unplug and
replug occurs?

>  	if (ret)
>  		dev_err(chip->dev, "failed to set role switch\n");

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260912225301.3396556-1-elson.serrao@oss.qualcomm.com?part=7