[PATCH net v3] net: ethernet: ti: am65-cpsw: Fix devlink port register sequence

[PATCH net v3] net: ethernet: ti: am65-cpsw: Fix devlink port register sequence

[Siddharth Vadapalli]

Renaming interfaces using udevd depends on the interface being registered
before its netdev is registered. Otherwise, udevd reads an empty
phys_port_name value, resulting in the interface not being renamed.

Fix this by registering the interface before registering its netdev
by invoking am65_cpsw_nuss_register_devlink() before invoking
register_netdev() for the interface.

Move the function call to devlink_port_type_eth_set(), invoking it after
register_netdev() is invoked, to ensure that netlink notification for the
port state change is generated after the netdev is completely initialized.

Fixes: 58356eb31d60 ("net: ti: am65-cpsw-nuss: Add devlink support")
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---
Changelog:
v2 -> v3:
1. Add error handling to unregister devlink.

v1-> v2:
1. Add Fixes tag in commit message.
2. Update patch subject to include "net".
3. Invoke devlink_port_type_eth_set() after register_netdev() is called.
4. Update commit message describing the cause for moving the call to
   devlink_port_type_eth_set().

v2: https://lore.kernel.org/r/20220704073040.7542-1-s-vadapalli@ti.com/
v1: https://lore.kernel.org/r/20220623044337.6179-1-s-vadapalli@ti.com/

 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index fb92d4c1547d..f4a6b590a1e3 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -2467,7 +2467,6 @@ static int am65_cpsw_nuss_register_devlink(struct am65_cpsw_common *common)
 				port->port_id, ret);
 			goto dl_port_unreg;
 		}
-		devlink_port_type_eth_set(dl_port, port->ndev);
 	}
 	devlink_register(common->devlink);
 	return ret;
@@ -2511,6 +2510,7 @@ static void am65_cpsw_unregister_devlink(struct am65_cpsw_common *common)
 static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
 {
 	struct device *dev = common->dev;
+	struct devlink_port *dl_port;
 	struct am65_cpsw_port *port;
 	int ret = 0, i;
 
@@ -2527,6 +2527,10 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
 		return ret;
 	}
 
+	ret = am65_cpsw_nuss_register_devlink(common);
+	if (ret)
+		return ret;
+
 	for (i = 0; i < common->port_num; i++) {
 		port = &common->ports[i];
 
@@ -2539,25 +2543,24 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
 				i, ret);
 			goto err_cleanup_ndev;
 		}
+
+		dl_port = &port->devlink_port;
+		devlink_port_type_eth_set(dl_port, port->ndev);
 	}
 
 	ret = am65_cpsw_register_notifiers(common);
 	if (ret)
 		goto err_cleanup_ndev;
 
-	ret = am65_cpsw_nuss_register_devlink(common);
-	if (ret)
-		goto clean_unregister_notifiers;
-
 	/* can't auto unregister ndev using devm_add_action() due to
 	 * devres release sequence in DD core for DMA
 	 */
 
 	return 0;
-clean_unregister_notifiers:
-	am65_cpsw_unregister_notifiers(common);
+
 err_cleanup_ndev:
 	am65_cpsw_nuss_cleanup_ndev(common);
+	am65_cpsw_unregister_devlink(common);
 
 	return ret;
 }
-- 
2.36.1

Re: [PATCH net v3] net: ethernet: ti: am65-cpsw: Fix devlink port register sequence

[Paolo Abeni]

On Wed, 2022-07-06 at 12:32 +0530, Siddharth Vadapalli wrote:
> Renaming interfaces using udevd depends on the interface being registered
> before its netdev is registered. Otherwise, udevd reads an empty
> phys_port_name value, resulting in the interface not being renamed.
> 
> Fix this by registering the interface before registering its netdev
> by invoking am65_cpsw_nuss_register_devlink() before invoking
> register_netdev() for the interface.
> 
> Move the function call to devlink_port_type_eth_set(), invoking it after
> register_netdev() is invoked, to ensure that netlink notification for the
> port state change is generated after the netdev is completely initialized.
> 
> Fixes: 58356eb31d60 ("net: ti: am65-cpsw-nuss: Add devlink support")
> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
> ---
> Changelog:
> v2 -> v3:
> 1. Add error handling to unregister devlink.
> 
> v1-> v2:
> 1. Add Fixes tag in commit message.
> 2. Update patch subject to include "net".
> 3. Invoke devlink_port_type_eth_set() after register_netdev() is called.
> 4. Update commit message describing the cause for moving the call to
>    devlink_port_type_eth_set().
> 
> v2: https://lore.kernel.org/r/20220704073040.7542-1-s-vadapalli@ti.com/
> v1: https://lore.kernel.org/r/20220623044337.6179-1-s-vadapalli@ti.com/
> 
>  drivers/net/ethernet/ti/am65-cpsw-nuss.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> index fb92d4c1547d..f4a6b590a1e3 100644
> --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> @@ -2467,7 +2467,6 @@ static int am65_cpsw_nuss_register_devlink(struct am65_cpsw_common *common)
>  				port->port_id, ret);
>  			goto dl_port_unreg;
>  		}
> -		devlink_port_type_eth_set(dl_port, port->ndev);
>  	}
>  	devlink_register(common->devlink);
>  	return ret;
> @@ -2511,6 +2510,7 @@ static void am65_cpsw_unregister_devlink(struct am65_cpsw_common *common)
>  static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
>  {
>  	struct device *dev = common->dev;
> +	struct devlink_port *dl_port;
>  	struct am65_cpsw_port *port;
>  	int ret = 0, i;
>  
> @@ -2527,6 +2527,10 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
>  		return ret;
>  	}
>  
> +	ret = am65_cpsw_nuss_register_devlink(common);
> +	if (ret)
> +		return ret;
> +
>  	for (i = 0; i < common->port_num; i++) {
>  		port = &common->ports[i];
>  
> @@ -2539,25 +2543,24 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
>  				i, ret);
>  			goto err_cleanup_ndev;
>  		}
> +
> +		dl_port = &port->devlink_port;
> +		devlink_port_type_eth_set(dl_port, port->ndev);
>  	}
>  
>  	ret = am65_cpsw_register_notifiers(common);
>  	if (ret)
>  		goto err_cleanup_ndev;
>  
> -	ret = am65_cpsw_nuss_register_devlink(common);
> -	if (ret)
> -		goto clean_unregister_notifiers;
> -
>  	/* can't auto unregister ndev using devm_add_action() due to
>  	 * devres release sequence in DD core for DMA
>  	 */
>  
>  	return 0;
> -clean_unregister_notifiers:
> -	am65_cpsw_unregister_notifiers(common);
> +
>  err_cleanup_ndev:
>  	am65_cpsw_nuss_cleanup_ndev(common);
> +	am65_cpsw_unregister_devlink(common);

It looks strange that there is no error path leading to
am65_cpsw_unregister_devlink() only.

Why we don't need to call it when/if devm_request_irq() fails? 

Not strictly related to this patch, but it looks like there is another
suspect cleanup point: if a 'register_netdev()' call fails, the cleanup
code will still call unregister_netdev() on the relevant device and the
later ones, hitting a WARN_ON(1) in unregister_netdevice_many().

Thanks!

Paolo

Re: [PATCH net v3] net: ethernet: ti: am65-cpsw: Fix devlink port register sequence

[Siddharth Vadapalli]

Hello Paolo,

On 07/07/22 13:00, Paolo Abeni wrote:
> On Wed, 2022-07-06 at 12:32 +0530, Siddharth Vadapalli wrote:
>> Renaming interfaces using udevd depends on the interface being registered
>> before its netdev is registered. Otherwise, udevd reads an empty
>> phys_port_name value, resulting in the interface not being renamed.
>>
>> Fix this by registering the interface before registering its netdev
>> by invoking am65_cpsw_nuss_register_devlink() before invoking
>> register_netdev() for the interface.
>>
>> Move the function call to devlink_port_type_eth_set(), invoking it after
>> register_netdev() is invoked, to ensure that netlink notification for the
>> port state change is generated after the netdev is completely initialized.
>>
>> Fixes: 58356eb31d60 ("net: ti: am65-cpsw-nuss: Add devlink support")
>> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
>> ---
>> Changelog:
>> v2 -> v3:
>> 1. Add error handling to unregister devlink.
>>
>> v1-> v2:
>> 1. Add Fixes tag in commit message.
>> 2. Update patch subject to include "net".
>> 3. Invoke devlink_port_type_eth_set() after register_netdev() is called.
>> 4. Update commit message describing the cause for moving the call to
>>    devlink_port_type_eth_set().
>>
>> v2: https://lore.kernel.org/r/20220704073040.7542-1-s-vadapalli@ti.com/
>> v1: https://lore.kernel.org/r/20220623044337.6179-1-s-vadapalli@ti.com/
>>
>>  drivers/net/ethernet/ti/am65-cpsw-nuss.c | 17 ++++++++++-------
>>  1 file changed, 10 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
>> index fb92d4c1547d..f4a6b590a1e3 100644
>> --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
>> +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
>> @@ -2467,7 +2467,6 @@ static int am65_cpsw_nuss_register_devlink(struct am65_cpsw_common *common)
>>  				port->port_id, ret);
>>  			goto dl_port_unreg;
>>  		}
>> -		devlink_port_type_eth_set(dl_port, port->ndev);
>>  	}
>>  	devlink_register(common->devlink);
>>  	return ret;
>> @@ -2511,6 +2510,7 @@ static void am65_cpsw_unregister_devlink(struct am65_cpsw_common *common)
>>  static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
>>  {
>>  	struct device *dev = common->dev;
>> +	struct devlink_port *dl_port;
>>  	struct am65_cpsw_port *port;
>>  	int ret = 0, i;
>>  
>> @@ -2527,6 +2527,10 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
>>  		return ret;
>>  	}
>>  
>> +	ret = am65_cpsw_nuss_register_devlink(common);
>> +	if (ret)
>> +		return ret;
>> +
>>  	for (i = 0; i < common->port_num; i++) {
>>  		port = &common->ports[i];
>>  
>> @@ -2539,25 +2543,24 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
>>  				i, ret);
>>  			goto err_cleanup_ndev;
>>  		}
>> +
>> +		dl_port = &port->devlink_port;
>> +		devlink_port_type_eth_set(dl_port, port->ndev);
>>  	}
>>  
>>  	ret = am65_cpsw_register_notifiers(common);
>>  	if (ret)
>>  		goto err_cleanup_ndev;
>>  
>> -	ret = am65_cpsw_nuss_register_devlink(common);
>> -	if (ret)
>> -		goto clean_unregister_notifiers;
>> -
>>  	/* can't auto unregister ndev using devm_add_action() due to
>>  	 * devres release sequence in DD core for DMA
>>  	 */
>>  
>>  	return 0;
>> -clean_unregister_notifiers:
>> -	am65_cpsw_unregister_notifiers(common);
>> +
>>  err_cleanup_ndev:
>>  	am65_cpsw_nuss_cleanup_ndev(common);
>> +	am65_cpsw_unregister_devlink(common);
> 
> It looks strange that there is no error path leading to
> am65_cpsw_unregister_devlink() only.
> 
> Why we don't need to call it when/if devm_request_irq() fails? 

am65_cpsw_nuss_register_devlink() is invoked after devm_request_irq() and
devm_request_irq()'s associated error handling.

> 
> Not strictly related to this patch, but it looks like there is another
> suspect cleanup point: if a 'register_netdev()' call fails, the cleanup
> code will still call unregister_netdev() on the relevant device and the
> later ones, hitting a WARN_ON(1) in unregister_netdevice_many().

Thank you for pointing it out. I will look at it and address it in a separate
cleanup patch.

Regards,
Siddharth.

Re: [PATCH net v3] net: ethernet: ti: am65-cpsw: Fix devlink port register sequence

[Paolo Abeni]

On Thu, 2022-07-07 at 14:41 +0530, Siddharth Vadapalli wrote:
> Hello Paolo,
> 
> On 07/07/22 13:00, Paolo Abeni wrote:
> > On Wed, 2022-07-06 at 12:32 +0530, Siddharth Vadapalli wrote:
> > > Renaming interfaces using udevd depends on the interface being registered
> > > before its netdev is registered. Otherwise, udevd reads an empty
> > > phys_port_name value, resulting in the interface not being renamed.
> > > 
> > > Fix this by registering the interface before registering its netdev
> > > by invoking am65_cpsw_nuss_register_devlink() before invoking
> > > register_netdev() for the interface.
> > > 
> > > Move the function call to devlink_port_type_eth_set(), invoking it after
> > > register_netdev() is invoked, to ensure that netlink notification for the
> > > port state change is generated after the netdev is completely initialized.
> > > 
> > > Fixes: 58356eb31d60 ("net: ti: am65-cpsw-nuss: Add devlink support")
> > > Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
> > > ---
> > > Changelog:
> > > v2 -> v3:
> > > 1. Add error handling to unregister devlink.
> > > 
> > > v1-> v2:
> > > 1. Add Fixes tag in commit message.
> > > 2. Update patch subject to include "net".
> > > 3. Invoke devlink_port_type_eth_set() after register_netdev() is called.
> > > 4. Update commit message describing the cause for moving the call to
> > >    devlink_port_type_eth_set().
> > > 
> > > v2: https://lore.kernel.org/r/20220704073040.7542-1-s-vadapalli@ti.com/
> > > v1: https://lore.kernel.org/r/20220623044337.6179-1-s-vadapalli@ti.com/
> > > 
> > >  drivers/net/ethernet/ti/am65-cpsw-nuss.c | 17 ++++++++++-------
> > >  1 file changed, 10 insertions(+), 7 deletions(-)
> > > 
> > > diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> > > index fb92d4c1547d..f4a6b590a1e3 100644
> > > --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> > > +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> > > @@ -2467,7 +2467,6 @@ static int am65_cpsw_nuss_register_devlink(struct am65_cpsw_common *common)
> > >  				port->port_id, ret);
> > >  			goto dl_port_unreg;
> > >  		}
> > > -		devlink_port_type_eth_set(dl_port, port->ndev);
> > >  	}
> > >  	devlink_register(common->devlink);
> > >  	return ret;
> > > @@ -2511,6 +2510,7 @@ static void am65_cpsw_unregister_devlink(struct am65_cpsw_common *common)
> > >  static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
> > >  {
> > >  	struct device *dev = common->dev;
> > > +	struct devlink_port *dl_port;
> > >  	struct am65_cpsw_port *port;
> > >  	int ret = 0, i;
> > >  
> > > @@ -2527,6 +2527,10 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
> > >  		return ret;
> > >  	}
> > >  
> > > +	ret = am65_cpsw_nuss_register_devlink(common);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > >  	for (i = 0; i < common->port_num; i++) {
> > >  		port = &common->ports[i];
> > >  
> > > @@ -2539,25 +2543,24 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
> > >  				i, ret);
> > >  			goto err_cleanup_ndev;
> > >  		}
> > > +
> > > +		dl_port = &port->devlink_port;
> > > +		devlink_port_type_eth_set(dl_port, port->ndev);
> > >  	}
> > >  
> > >  	ret = am65_cpsw_register_notifiers(common);
> > >  	if (ret)
> > >  		goto err_cleanup_ndev;
> > >  
> > > -	ret = am65_cpsw_nuss_register_devlink(common);
> > > -	if (ret)
> > > -		goto clean_unregister_notifiers;
> > > -
> > >  	/* can't auto unregister ndev using devm_add_action() due to
> > >  	 * devres release sequence in DD core for DMA
> > >  	 */
> > >  
> > >  	return 0;
> > > -clean_unregister_notifiers:
> > > -	am65_cpsw_unregister_notifiers(common);
> > > +
> > >  err_cleanup_ndev:
> > >  	am65_cpsw_nuss_cleanup_ndev(common);
> > > +	am65_cpsw_unregister_devlink(common);
> > 
> > It looks strange that there is no error path leading to
> > am65_cpsw_unregister_devlink() only.
> > 
> > Why we don't need to call it when/if devm_request_irq() fails? 
> 
> am65_cpsw_nuss_register_devlink() is invoked after devm_request_irq() and
> devm_request_irq()'s associated error handling.

Whoops, I misread the exact location were
am65_cpsw_nuss_register_devlink() is located after this patch.  

That error path now LGTM.

> > 
> > Not strictly related to this patch, but it looks like there is another
> > suspect cleanup point: if a 'register_netdev()' call fails, the cleanup
> > code will still call unregister_netdev() on the relevant device and the
> > later ones, hitting a WARN_ON(1) in unregister_netdevice_many().
> 
> Thank you for pointing it out. I will look at it and address it in a separate
> cleanup patch.

Thanks!

Paolo

Re: [PATCH net v3] net: ethernet: ti: am65-cpsw: Fix devlink port register sequence

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Wed, 6 Jul 2022 12:32:08 +0530 you wrote:
> Renaming interfaces using udevd depends on the interface being registered
> before its netdev is registered. Otherwise, udevd reads an empty
> phys_port_name value, resulting in the interface not being renamed.
> 
> Fix this by registering the interface before registering its netdev
> by invoking am65_cpsw_nuss_register_devlink() before invoking
> register_netdev() for the interface.
> 
> [...]

Here is the summary with links:
  - [net,v3] net: ethernet: ti: am65-cpsw: Fix devlink port register sequence
    https://git.kernel.org/netdev/net/c/0680e20af5fb

You are awesome, thank you!
-- 
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