[v2,22/28] mfd: core: Ensure disabled devices are skiped without aborting

Message ID 20230726150225.483464-23-herve.codina@bootlin.com
State New
Headers
Series Add support for QMC HDLC, framer infrastruture and PEF2256 framer |

Commit Message

Herve Codina July 26, 2023, 3:02 p.m. UTC
  The loop searching for a matching device based on its compatible
string is aborted when a matching disabled device is found.
This abort avoid to add devices as soon as one disabled device
is found.

Continue searching for an other device instead of aborting on the
first disabled one fixes the issue.

Fixes: 22380b65dc70 ("mfd: mfd-core: Ensure disabled devices are ignored without error")
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 drivers/mfd/mfd-core.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)
  

Comments

Lee Jones July 27, 2023, 9:22 a.m. UTC | #1
On Wed, 26 Jul 2023, Herve Codina wrote:

> The loop searching for a matching device based on its compatible
> string is aborted when a matching disabled device is found.
> This abort avoid to add devices as soon as one disabled device
> is found.
> 
> Continue searching for an other device instead of aborting on the
> first disabled one fixes the issue.
> 
> Fixes: 22380b65dc70 ("mfd: mfd-core: Ensure disabled devices are ignored without error")
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> ---
>  drivers/mfd/mfd-core.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> index 0ed7c0d7784e..bcc26e64639a 100644
> --- a/drivers/mfd/mfd-core.c
> +++ b/drivers/mfd/mfd-core.c
> @@ -146,6 +146,7 @@ static int mfd_add_device(struct device *parent, int id,
>  	struct platform_device *pdev;
>  	struct device_node *np = NULL;
>  	struct mfd_of_node_entry *of_entry, *tmp;
> +	bool disabled;
>  	int ret = -ENOMEM;
>  	int platform_id;
>  	int r;
> @@ -181,13 +182,13 @@ static int mfd_add_device(struct device *parent, int id,
>  		goto fail_res;
>  
>  	if (IS_ENABLED(CONFIG_OF) && parent->of_node && cell->of_compatible) {
> +		disabled = false;

This does not appear to reside in a loop.

Why not set it to false on declaration?

>  		for_each_child_of_node(parent->of_node, np) {
>  			if (of_device_is_compatible(np, cell->of_compatible)) {
> -				/* Ignore 'disabled' devices error free */
> +				/* Skip 'disabled' devices */
>  				if (!of_device_is_available(np)) {
> -					of_node_put(np);

Doesn't this result in a resource leak?

> -					ret = 0;
> -					goto fail_alias;
> +					disabled = true;
> +					continue;
>  				}
>  
>  				ret = mfd_match_of_node_to_dev(pdev, np, cell);
> @@ -197,10 +198,17 @@ static int mfd_add_device(struct device *parent, int id,
>  				if (ret)
>  					goto fail_alias;
>  
> -				break;
> +				goto match;
>  			}
>  		}
>  
> +		if (disabled) {
> +			/* Ignore 'disabled' devices error free */
> +			ret = 0;
> +			goto fail_alias;
> +		}
> +
> +match:
>  		if (!pdev->dev.of_node)
>  			pr_warn("%s: Failed to locate of_node [id: %d]\n",
>  				cell->name, platform_id);
> -- 
> 2.41.0
>
  
Herve Codina July 27, 2023, 10:18 a.m. UTC | #2
Hi Lee,

On Thu, 27 Jul 2023 10:22:09 +0100
Lee Jones <lee@kernel.org> wrote:

> On Wed, 26 Jul 2023, Herve Codina wrote:
> 
> > The loop searching for a matching device based on its compatible
> > string is aborted when a matching disabled device is found.
> > This abort avoid to add devices as soon as one disabled device
> > is found.
> > 
> > Continue searching for an other device instead of aborting on the
> > first disabled one fixes the issue.
> > 
> > Fixes: 22380b65dc70 ("mfd: mfd-core: Ensure disabled devices are ignored without error")
> > Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> > ---
> >  drivers/mfd/mfd-core.c | 18 +++++++++++++-----
> >  1 file changed, 13 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> > index 0ed7c0d7784e..bcc26e64639a 100644
> > --- a/drivers/mfd/mfd-core.c
> > +++ b/drivers/mfd/mfd-core.c
> > @@ -146,6 +146,7 @@ static int mfd_add_device(struct device *parent, int id,
> >  	struct platform_device *pdev;
> >  	struct device_node *np = NULL;
> >  	struct mfd_of_node_entry *of_entry, *tmp;
> > +	bool disabled;
> >  	int ret = -ENOMEM;
> >  	int platform_id;
> >  	int r;
> > @@ -181,13 +182,13 @@ static int mfd_add_device(struct device *parent, int id,
> >  		goto fail_res;
> >  
> >  	if (IS_ENABLED(CONFIG_OF) && parent->of_node && cell->of_compatible) {
> > +		disabled = false;  
> 
> This does not appear to reside in a loop.
> 
> Why not set it to false on declaration?

Indeed, I will change in the next iteration and set the value to false at
the declaration.

> 
> >  		for_each_child_of_node(parent->of_node, np) {
> >  			if (of_device_is_compatible(np, cell->of_compatible)) {
> > -				/* Ignore 'disabled' devices error free */
> > +				/* Skip 'disabled' devices */
> >  				if (!of_device_is_available(np)) {
> > -					of_node_put(np);  
> 
> Doesn't this result in a resource leak?

No because we change from 'goto fail_alias' to 'continue' and so we don't
exit from the for_each_child_of_node().
The for_each_child_of_node() calls of_get_next_child() and, in turn, calls
of_node_put().

Regards,
Hervé

> 
> > -					ret = 0;
> > -					goto fail_alias;
> > +					disabled = true;
> > +					continue;
> >  				}
> >  
> >  				ret = mfd_match_of_node_to_dev(pdev, np, cell);
> > @@ -197,10 +198,17 @@ static int mfd_add_device(struct device *parent, int id,
> >  				if (ret)
> >  					goto fail_alias;
> >  
> > -				break;
> > +				goto match;
> >  			}
> >  		}
> >  
> > +		if (disabled) {
> > +			/* Ignore 'disabled' devices error free */
> > +			ret = 0;
> > +			goto fail_alias;
> > +		}
> > +
> > +match:
> >  		if (!pdev->dev.of_node)
> >  			pr_warn("%s: Failed to locate of_node [id: %d]\n",
> >  				cell->name, platform_id);
> > -- 
> > 2.41.0
> >   
>
  
Christophe Leroy Aug. 8, 2023, 8:13 a.m. UTC | #3
Le 26/07/2023 à 17:02, Herve Codina a écrit :
> The loop searching for a matching device based on its compatible
> string is aborted when a matching disabled device is found.
> This abort avoid to add devices as soon as one disabled device
> is found.

s/avoid/prevents/

> 
> Continue searching for an other device instead of aborting on the
> first disabled one fixes the issue.
> 
> Fixes: 22380b65dc70 ("mfd: mfd-core: Ensure disabled devices are ignored without error")
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>

> ---
>   drivers/mfd/mfd-core.c | 18 +++++++++++++-----
>   1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> index 0ed7c0d7784e..bcc26e64639a 100644
> --- a/drivers/mfd/mfd-core.c
> +++ b/drivers/mfd/mfd-core.c
> @@ -146,6 +146,7 @@ static int mfd_add_device(struct device *parent, int id,
>   	struct platform_device *pdev;
>   	struct device_node *np = NULL;
>   	struct mfd_of_node_entry *of_entry, *tmp;
> +	bool disabled;
>   	int ret = -ENOMEM;
>   	int platform_id;
>   	int r;
> @@ -181,13 +182,13 @@ static int mfd_add_device(struct device *parent, int id,
>   		goto fail_res;
>   
>   	if (IS_ENABLED(CONFIG_OF) && parent->of_node && cell->of_compatible) {
> +		disabled = false;
>   		for_each_child_of_node(parent->of_node, np) {
>   			if (of_device_is_compatible(np, cell->of_compatible)) {
> -				/* Ignore 'disabled' devices error free */
> +				/* Skip 'disabled' devices */
>   				if (!of_device_is_available(np)) {
> -					of_node_put(np);
> -					ret = 0;
> -					goto fail_alias;
> +					disabled = true;
> +					continue;
>   				}
>   
>   				ret = mfd_match_of_node_to_dev(pdev, np, cell);
> @@ -197,10 +198,17 @@ static int mfd_add_device(struct device *parent, int id,
>   				if (ret)
>   					goto fail_alias;
>   
> -				break;
> +				goto match;
>   			}
>   		}
>   
> +		if (disabled) {
> +			/* Ignore 'disabled' devices error free */
> +			ret = 0;
> +			goto fail_alias;
> +		}
> +
> +match:
>   		if (!pdev->dev.of_node)
>   			pr_warn("%s: Failed to locate of_node [id: %d]\n",
>   				cell->name, platform_id);
  
Herve Codina Aug. 8, 2023, 8:44 a.m. UTC | #4
On Tue, 8 Aug 2023 08:13:27 +0000
Christophe Leroy <christophe.leroy@csgroup.eu> wrote:

> Le 26/07/2023 à 17:02, Herve Codina a écrit :
> > The loop searching for a matching device based on its compatible
> > string is aborted when a matching disabled device is found.
> > This abort avoid to add devices as soon as one disabled device
> > is found.  
> 
> s/avoid/prevents/

Yes, will be changed.

> 
> > 
> > Continue searching for an other device instead of aborting on the
> > first disabled one fixes the issue.
> > 
> > Fixes: 22380b65dc70 ("mfd: mfd-core: Ensure disabled devices are ignored without error")
> > Signed-off-by: Herve Codina <herve.codina@bootlin.com>  
> 
> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>
  

Patch

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index 0ed7c0d7784e..bcc26e64639a 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -146,6 +146,7 @@  static int mfd_add_device(struct device *parent, int id,
 	struct platform_device *pdev;
 	struct device_node *np = NULL;
 	struct mfd_of_node_entry *of_entry, *tmp;
+	bool disabled;
 	int ret = -ENOMEM;
 	int platform_id;
 	int r;
@@ -181,13 +182,13 @@  static int mfd_add_device(struct device *parent, int id,
 		goto fail_res;
 
 	if (IS_ENABLED(CONFIG_OF) && parent->of_node && cell->of_compatible) {
+		disabled = false;
 		for_each_child_of_node(parent->of_node, np) {
 			if (of_device_is_compatible(np, cell->of_compatible)) {
-				/* Ignore 'disabled' devices error free */
+				/* Skip 'disabled' devices */
 				if (!of_device_is_available(np)) {
-					of_node_put(np);
-					ret = 0;
-					goto fail_alias;
+					disabled = true;
+					continue;
 				}
 
 				ret = mfd_match_of_node_to_dev(pdev, np, cell);
@@ -197,10 +198,17 @@  static int mfd_add_device(struct device *parent, int id,
 				if (ret)
 					goto fail_alias;
 
-				break;
+				goto match;
 			}
 		}
 
+		if (disabled) {
+			/* Ignore 'disabled' devices error free */
+			ret = 0;
+			goto fail_alias;
+		}
+
+match:
 		if (!pdev->dev.of_node)
 			pr_warn("%s: Failed to locate of_node [id: %d]\n",
 				cell->name, platform_id);