Re: [PATCH v3 7/9] Bluetooth: hci_qca: Add M.2 Bluetooth device support using pwrseq

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Resource leak due to `devm_pwrseq_get()` being tied to the parent UART controller device instead of the serdev device being probed.
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commit cdecabb47fcbe744365c9b9d2fe977b061bcd9d4
Author: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

Bluetooth: hci_qca: Add M.2 Bluetooth device support using pwrseq

This commit adds support for controlling the power supply to an M.2 Bluetooth
device using the uart pwrseq device. It retrieves the pwrseq device if an
OF graph link is present on the controller device.

> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index cd1834246b479..c83fe72bc5499 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
[ ... ]
> @@ -2443,6 +2444,18 @@ static int qca_serdev_probe(struct serdev_device *serdev)
>  	case QCA_WCN6750:
>  	case QCA_WCN6855:
>  	case QCA_WCN7850:
> +		/*
> +		 * OF graph link is only present for BT devices attached through
> +		 * the M.2 Key E connector.
> +		 */
> +		if (of_graph_is_present(dev_of_node(&serdev->ctrl->dev))) {
> +			qcadev->bt_power->pwrseq = devm_pwrseq_get(&serdev->ctrl->dev,
> +								   "uart");

Does this leak the pwrseq descriptor if the probe fails later or the driver
is unbound?

By passing &serdev->ctrl->dev to devm_pwrseq_get(), the devres cleanup
action is attached to the parent UART controller's lifecycle rather than the
Bluetooth serdev device (&serdev->dev) currently being probed.

If the driver probe fails in subsequent steps (like hci_uart_register_device),
the driver core cleans up devres allocations for &serdev->dev, but this
allocation would remain permanently attached to the still-active parent
&serdev->ctrl->dev device.

Could this cause multiple leaks and keep the provider's module reference
elevated during repeated probe deferrals or bind/unbind cycles?

> +			if (IS_ERR(qcadev->bt_power->pwrseq))
> +				return PTR_ERR(qcadev->bt_power->pwrseq);
> +			break;
> +		}
> +
>  		if (!device_property_present(&serdev->dev, "enable-gpios")) {
>  			/*
>  			 * Backward compatibility with old DT sources. If the

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Sashiko AI review · https://sashiko.dev/#/patchset/20260519-pwrseq-m2-bt-v3-0-b39dc2ae3966@oss.qualcomm.com?part=7