[PATCH v2] pmdomain: imx8m-blk-ctrl: imx8mp-blk-ctrl: Error out if domains are missing in DT

[Marek Vasut <marex@denx.de>]

This driver assumes that domain->power_dev is non-NULL in its suspend/resume
path. The assumption is valid, since all the devices that are being looked up
here should be described in DT. In case they are not described in DT, beause
the DT is faulty, suspend/resume attempt would trigger NULL pointer dereference.
To avoid this failure, check whether the power_dev assignment is not NULL right
away in probe callback and fail early if it is.

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Jindong Yue <jindong.yue@nxp.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Marco Felsch <m.felsch@pengutronix.de>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-pm@vger.kernel.org
---
V2: Add extra check for domain being NULL (thanks Peng)
---
 drivers/pmdomain/imx/imx8m-blk-ctrl.c  | 9 ++++++---
 drivers/pmdomain/imx/imx8mp-blk-ctrl.c | 9 ++++++---
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
index 1341a707f61bc..ca942d7929c2b 100644
--- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
+++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
@@ -258,11 +258,14 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
 
 		domain->power_dev =
 			dev_pm_domain_attach_by_name(dev, data->gpc_name);
-		if (IS_ERR(domain->power_dev)) {
-			dev_err_probe(dev, PTR_ERR(domain->power_dev),
+		if (IS_ERR_OR_NULL(domain->power_dev)) {
+			if (!domain->power_dev)
+				ret = -ENODEV;
+			else
+				ret = PTR_ERR(domain->power_dev);
+			dev_err_probe(dev, ret,
 				      "failed to attach power domain \"%s\"\n",
 				      data->gpc_name);
-			ret = PTR_ERR(domain->power_dev);
 			goto cleanup_pds;
 		}
 
diff --git a/drivers/pmdomain/imx/imx8mp-blk-ctrl.c b/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
index e3203eb6a0229..e488cf79b8007 100644
--- a/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
+++ b/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
@@ -687,11 +687,14 @@ static int imx8mp_blk_ctrl_probe(struct platform_device *pdev)
 
 		domain->power_dev =
 			dev_pm_domain_attach_by_name(dev, data->gpc_name);
-		if (IS_ERR(domain->power_dev)) {
-			dev_err_probe(dev, PTR_ERR(domain->power_dev),
+		if (IS_ERR_OR_NULL(domain->power_dev)) {
+			if (!domain->power_dev)
+				ret = -ENODEV;
+			else
+				ret = PTR_ERR(domain->power_dev);
+			dev_err_probe(dev, ret,
 				      "failed to attach power domain %s\n",
 				      data->gpc_name);
-			ret = PTR_ERR(domain->power_dev);
 			goto cleanup_pds;
 		}
 
-- 
2.43.0