diff mbox series

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

Message ID 20240119014807.268694-1-marex@denx.de (mailing list archive)
State New, archived
Headers show
Series [v2] pmdomain: imx8m-blk-ctrl: imx8mp-blk-ctrl: Error out if domains are missing in DT | expand

Commit Message

Marek Vasut Jan. 19, 2024, 1:47 a.m. UTC
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(-)

Comments

Peng Fan Jan. 19, 2024, 1:54 a.m. UTC | #1
> Subject: [PATCH v2] 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@denx.de>

Reviewed-by: Peng Fan <peng.fan@nxp.com>
> ---
> 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
Uwe Kleine-König Jan. 19, 2024, 7:42 a.m. UTC | #2
On Fri, Jan 19, 2024 at 02:47:41AM +0100, Marek Vasut wrote:
> 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);

This could be made a bit more compact using:

	domain->power_dev =
		dev_pm_domain_attach_by_name(dev, data->gpc_name) ||
		ERR_PTR(-ENODEV);
	if (IS_ERR(domain->power_dev)) {
		ret = PTR_ERR(domain->power_dev);
		...

I'm unsure though if this is human friendly enough?!

Having said that I wonder about dev_pm_domain_attach_by_name(). IMHO if
NULL is an error case it and other errors are signaled by error
pointers, there is something to fix there.

Best regards
Uwe
Marek Vasut Jan. 19, 2024, 10:58 a.m. UTC | #3
On 1/19/24 08:42, Uwe Kleine-König wrote:
> On Fri, Jan 19, 2024 at 02:47:41AM +0100, Marek Vasut wrote:
>> 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);
> 
> This could be made a bit more compact using:
> 
> 	domain->power_dev =
> 		dev_pm_domain_attach_by_name(dev, data->gpc_name) ||
> 		ERR_PTR(-ENODEV);
> 	if (IS_ERR(domain->power_dev)) {
> 		ret = PTR_ERR(domain->power_dev);
> 		...
> 
> I'm unsure though if this is human friendly enough?!

I think it is only more cryptic and doesn't improve readability.

> Having said that I wonder about dev_pm_domain_attach_by_name(). IMHO if
> NULL is an error case it and other errors are signaled by error
> pointers, there is something to fix there.

I don't think dev_pm_domain_attach_by_name() returning NULL is an error 
-- the domain may be missing from DT and that is legitimate use case I 
think.

But not here, where all the domains should be described in DT because 
the driver makes assumptions about their presence in the suspend/resume 
part, and because the DT should fully describe the domains of this 
hardware anyway, so we better catch such DT issues.
Ulf Hansson Jan. 22, 2024, 3:21 p.m. UTC | #4
On Fri, 19 Jan 2024 at 02:48, Marek Vasut <marex@denx.de> wrote:
>
> 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>

Applied for next, thanks!

Kind regards
Uffe


> ---
> 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
>
diff mbox series

Patch

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;
 		}