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

[Peng Fan]

> Subject: [PATCH] pmdomain: imx8m-blk-ctrl: imx8mp-blk-ctrl: Error out if
> domains are missing in DT
> 
> 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
> ---
>  drivers/pmdomain/imx/imx8m-blk-ctrl.c  | 2 +-
> drivers/pmdomain/imx/imx8mp-blk-ctrl.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> index 1341a707f61bc..1b83c9c2d5b77 100644
> --- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> +++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> @@ -258,7 +258,7 @@ 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)) {
> +		if (IS_ERR_OR_NULL(domain->power_dev)) {

The ret = PTR_ERR(domain->power_dev) will make the probe return
success if domain->power_dev is NULL.

Regards,
Peng.

>  			dev_err_probe(dev, PTR_ERR(domain->power_dev),
>  				      "failed to attach power domain
> \"%s\"\n",
>  				      data->gpc_name);
> diff --git a/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
> b/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
> index e3203eb6a0229..3d6888afb416c 100644
> --- a/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
> +++ b/drivers/pmdomain/imx/imx8mp-blk-ctrl.c
> @@ -687,7 +687,7 @@ 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)) {
> +		if (IS_ERR_OR_NULL(domain->power_dev)) {
>  			dev_err_probe(dev, PTR_ERR(domain->power_dev),
>  				      "failed to attach power domain %s\n",
>  				      data->gpc_name);
> --
> 2.43.0