diff mbox series

[v1,1/3] usb: typec: intel_pmc_mux: Put fwnode in error case during ->probe()

Message ID 20210606200911.32076-1-andy.shevchenko@gmail.com
State New
Headers show
Series [v1,1/3] usb: typec: intel_pmc_mux: Put fwnode in error case during ->probe() | expand

Commit Message

Andy Shevchenko June 6, 2021, 8:09 p.m. UTC
device_get_next_child_node() bumps a reference counting of a returned variable.
We have to balance it whenever we return to the caller.

Fixes: 6701adfa9693 ("usb: typec: driver for Intel PMC mux control")
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
 drivers/usb/typec/mux/intel_pmc_mux.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Heikki Krogerus June 7, 2021, 9:23 a.m. UTC | #1
On Sun, Jun 06, 2021 at 11:09:09PM +0300, Andy Shevchenko wrote:
> device_get_next_child_node() bumps a reference counting of a returned variable.

> We have to balance it whenever we return to the caller.

> 

> Fixes: 6701adfa9693 ("usb: typec: driver for Intel PMC mux control")

> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> ---

>  drivers/usb/typec/mux/intel_pmc_mux.c | 1 +

>  1 file changed, 1 insertion(+)

> 

> diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c

> index 46a25b8db72e..134325444e6a 100644

> --- a/drivers/usb/typec/mux/intel_pmc_mux.c

> +++ b/drivers/usb/typec/mux/intel_pmc_mux.c

> @@ -645,6 +645,7 @@ static int pmc_usb_probe(struct platform_device *pdev)

>  	return 0;

>  

>  err_remove_ports:

> +	fwnode_handle_put(fwnode);


Wouldn't it be more clear to do that in the condition that jumps to
this lable?

>  	for (i = 0; i < pmc->num_ports; i++) {

>  		typec_switch_unregister(pmc->port[i].typec_sw);

>  		typec_mux_unregister(pmc->port[i].typec_mux);

> -- 

> 2.31.1


-- 
heikki
Heikki Krogerus June 7, 2021, 9:26 a.m. UTC | #2
On Sun, Jun 06, 2021 at 11:09:11PM +0300, Andy Shevchenko wrote:
> For ACPI devices we have a symmetric API to put them, so use it in the driver.

> 

> Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>


Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>


> ---

>  drivers/usb/typec/mux/intel_pmc_mux.c | 8 ++++----

>  1 file changed, 4 insertions(+), 4 deletions(-)

> 

> diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c

> index de40276cc18b..2d0a863956c7 100644

> --- a/drivers/usb/typec/mux/intel_pmc_mux.c

> +++ b/drivers/usb/typec/mux/intel_pmc_mux.c

> @@ -582,12 +582,12 @@ static int pmc_usb_probe_iom(struct pmc_usb *pmc)

>  	acpi_dev_free_resource_list(&resource_list);

>  

>  	if (!pmc->iom_base) {

> -		put_device(&adev->dev);

> +		acpi_dev_put(adev);

>  		return -ENOMEM;

>  	}

>  

>  	if (IS_ERR(pmc->iom_base)) {

> -		put_device(&adev->dev);

> +		acpi_dev_put(adev);

>  		return PTR_ERR(pmc->iom_base);

>  	}

>  

> @@ -657,7 +657,7 @@ static int pmc_usb_probe(struct platform_device *pdev)

>  		usb_role_switch_unregister(pmc->port[i].usb_sw);

>  	}

>  

> -	put_device(&pmc->iom_adev->dev);

> +	acpi_dev_put(pmc->iom_adev);

>  

>  	return ret;

>  }

> @@ -673,7 +673,7 @@ static int pmc_usb_remove(struct platform_device *pdev)

>  		usb_role_switch_unregister(pmc->port[i].usb_sw);

>  	}

>  

> -	put_device(&pmc->iom_adev->dev);

> +	acpi_dev_put(pmc->iom_adev);

>  

>  	return 0;

>  }

> -- 

> 2.31.1


-- 
heikki
Andy Shevchenko June 7, 2021, 9:29 a.m. UTC | #3
On Mon, Jun 7, 2021 at 12:23 PM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
> On Sun, Jun 06, 2021 at 11:09:09PM +0300, Andy Shevchenko wrote:

> > device_get_next_child_node() bumps a reference counting of a returned variable.


...

> >  err_remove_ports:

> > +     fwnode_handle_put(fwnode);

>

> Wouldn't it be more clear to do that in the condition that jumps to

> this lable?


In this case it doesn't matter. As a general pattern, no, because this
will help to keep this in mind in complex error handling ladders. That
said, I prefer my variant unless there is a strong opinion to move it
into the conditional.

> >       for (i = 0; i < pmc->num_ports; i++) {

> >               typec_switch_unregister(pmc->port[i].typec_sw);

> >               typec_mux_unregister(pmc->port[i].typec_mux);



-- 
With Best Regards,
Andy Shevchenko
Heikki Krogerus June 7, 2021, 9:49 a.m. UTC | #4
On Mon, Jun 07, 2021 at 12:29:53PM +0300, Andy Shevchenko wrote:
> On Mon, Jun 7, 2021 at 12:23 PM Heikki Krogerus

> <heikki.krogerus@linux.intel.com> wrote:

> > On Sun, Jun 06, 2021 at 11:09:09PM +0300, Andy Shevchenko wrote:

> > > device_get_next_child_node() bumps a reference counting of a returned variable.

> 

> ...

> 

> > >  err_remove_ports:

> > > +     fwnode_handle_put(fwnode);

> >

> > Wouldn't it be more clear to do that in the condition that jumps to

> > this lable?

> 

> In this case it doesn't matter. As a general pattern, no, because this

> will help to keep this in mind in complex error handling ladders. That

> said, I prefer my variant unless there is a strong opinion to move it

> into the conditional.


Now it looks like you are releasing the mux device fwnode instead of a
port fwnode because everything else related to the ports is destroyed
in below loop. That's too confusing.

Just handle it inside the condition, and the whole thing becomes
clear.

> > >       for (i = 0; i < pmc->num_ports; i++) {

> > >               typec_switch_unregister(pmc->port[i].typec_sw);

> > >               typec_mux_unregister(pmc->port[i].typec_mux);


-- 
heikki
Andy Shevchenko June 7, 2021, 9:51 a.m. UTC | #5
On Mon, Jun 7, 2021 at 12:49 PM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
> On Mon, Jun 07, 2021 at 12:29:53PM +0300, Andy Shevchenko wrote:

> > On Mon, Jun 7, 2021 at 12:23 PM Heikki Krogerus

> > <heikki.krogerus@linux.intel.com> wrote:

> > > On Sun, Jun 06, 2021 at 11:09:09PM +0300, Andy Shevchenko wrote:

> > > > device_get_next_child_node() bumps a reference counting of a returned variable.

> >

> > ...

> >

> > > >  err_remove_ports:

> > > > +     fwnode_handle_put(fwnode);

> > >

> > > Wouldn't it be more clear to do that in the condition that jumps to

> > > this lable?

> >

> > In this case it doesn't matter. As a general pattern, no, because this

> > will help to keep this in mind in complex error handling ladders. That

> > said, I prefer my variant unless there is a strong opinion to move it

> > into the conditional.

>

> Now it looks like you are releasing the mux device fwnode instead of a

> port fwnode because everything else related to the ports is destroyed

> in below loop. That's too confusing.

>

> Just handle it inside the condition, and the whole thing becomes

> clear.


I see your point, okay, I will update in v2.
Thanks for your review!

> > > >       for (i = 0; i < pmc->num_ports; i++) {

> > > >               typec_switch_unregister(pmc->port[i].typec_sw);

> > > >               typec_mux_unregister(pmc->port[i].typec_mux);


-- 
With Best Regards,
Andy Shevchenko
diff mbox series

Patch

diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c
index 46a25b8db72e..134325444e6a 100644
--- a/drivers/usb/typec/mux/intel_pmc_mux.c
+++ b/drivers/usb/typec/mux/intel_pmc_mux.c
@@ -645,6 +645,7 @@  static int pmc_usb_probe(struct platform_device *pdev)
 	return 0;
 
 err_remove_ports:
+	fwnode_handle_put(fwnode);
 	for (i = 0; i < pmc->num_ports; i++) {
 		typec_switch_unregister(pmc->port[i].typec_sw);
 		typec_mux_unregister(pmc->port[i].typec_mux);