[PATCH RFC] pmdomain: imx: reject a missing bus power domain

[Slavin Liu <bolin.liu@seu.edu.cn>]

The named-domain attach API may return NULL for an absent name.
Treat that as -ENODEV before publishing bus_power_dev to later unwind
paths, without changing the handling of existing error pointers.

Detected by static analysis and reviewed with AI-assisted source auditing.

Fixes: 2684ac05a8c4 ("soc: imx: add i.MX8M blk-ctrl driver")
Fixes: 556f5cf9568a ("soc: imx: add i.MX8MP HSIO blk-ctrl")
Assisted-by: LLM
Signed-off-by: Slavin Liu <bolin.liu@seu.edu.cn>
---
 drivers/pmdomain/imx/imx8m-blk-ctrl.c  | 2 ++
 drivers/pmdomain/imx/imx8mp-blk-ctrl.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
index 479789009c7f..9653a8ac9a6e 100644
--- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
+++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
@@ -228,6 +228,8 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	bc->bus_power_dev = dev_pm_domain_attach_by_name(dev, "bus");
+	if (!bc->bus_power_dev)
+		return dev_err_probe(dev, -ENODEV, "missing bus power domain\n");
 	if (IS_ERR(bc->bus_power_dev)) {
 		if (PTR_ERR(bc->bus_power_dev) == -ENODEV)
 			return dev_err_probe(dev, -EPROBE_DEFER,
diff --git a/drivers/pmdomain/imx/imx8mp-blk-ctrl.c b/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
index d255c20f58e2..e952b4ee75c0 100644
--- a/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
+++ b/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
@@ -655,6 +655,8 @@ static int imx8mp_blk_ctrl_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	bc->bus_power_dev = dev_pm_domain_attach_by_name(dev, "bus");
+	if (!bc->bus_power_dev)
+		return dev_err_probe(dev, -ENODEV, "missing bus power domain\n");
 	if (IS_ERR(bc->bus_power_dev))
 		return dev_err_probe(dev, PTR_ERR(bc->bus_power_dev),
 				     "failed to attach bus power domain\n");