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

[Marek Vasut]

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 at denx.de>
---
Cc: "Uwe Kleine-König" <u.kleine-koenig at pengutronix.de>
Cc: Fabio Estevam <festevam at gmail.com>
Cc: Jindong Yue <jindong.yue at nxp.com>
Cc: Lucas Stach <l.stach at pengutronix.de>
Cc: Marco Felsch <m.felsch at pengutronix.de>
Cc: NXP Linux Team <linux-imx at nxp.com>
Cc: Peng Fan <peng.fan at nxp.com>
Cc: Pengutronix Kernel Team <kernel at pengutronix.de>
Cc: Sascha Hauer <s.hauer at pengutronix.de>
Cc: Shawn Guo <shawnguo at kernel.org>
Cc: Ulf Hansson <ulf.hansson at linaro.org>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-pm at 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