[PATCH] net: dsa: mv88e6xxx: initialize return variable on declaration

[PATCH] net: dsa: mv88e6xxx: initialize return variable on declaration

[Ameer Hamza]

Uninitialized err variable defined in mv88e6393x_serdes_power
function may cause undefined behaviour if it is called from
mv88e6xxx_serdes_power_down context.

Addresses-Coverity: 1494644 ("Uninitialized scalar variable")

Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
---
 drivers/net/dsa/mv88e6xxx/serdes.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 55273013bfb5..33727439724a 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -1507,7 +1507,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			    bool on)
 {
 	u8 cmode = chip->ports[port].cmode;
-	int err;
+	int err = 0;
 
 	if (port != 0 && port != 9 && port != 10)
 		return -EOPNOTSUPP;
-- 
2.25.1

Re: [PATCH] net: dsa: mv88e6xxx: initialize return variable on declaration

[Andrew Lunn]

On Mon, Dec 06, 2021 at 04:32:19PM +0500, Ameer Hamza wrote:
> Uninitialized err variable defined in mv88e6393x_serdes_power
> function may cause undefined behaviour if it is called from
> mv88e6xxx_serdes_power_down context.
> 
> Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
> 
> Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
> ---
>  drivers/net/dsa/mv88e6xxx/serdes.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
> index 55273013bfb5..33727439724a 100644
> --- a/drivers/net/dsa/mv88e6xxx/serdes.c
> +++ b/drivers/net/dsa/mv88e6xxx/serdes.c
> @@ -1507,7 +1507,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  			    bool on)
>  {
>  	u8 cmode = chip->ports[port].cmode;
> -	int err;
> +	int err = 0;
>  
>  	if (port != 0 && port != 9 && port != 10)
>  		return -EOPNOTSUPP;

Hi Marek

This warning likely comes from cmode not being a SERDES mode, and that
is not handles in the switch statementing. Do we want an

default:
	err = EINVAL;

?

	Andrew

Re: [PATCH] net: dsa: mv88e6xxx: initialize return variable on declaration

[Marek Behún]

On Mon, 6 Dec 2021 14:21:03 +0100
Andrew Lunn <andrew@lunn.ch> wrote:

> On Mon, Dec 06, 2021 at 04:32:19PM +0500, Ameer Hamza wrote:
> > Uninitialized err variable defined in mv88e6393x_serdes_power
> > function may cause undefined behaviour if it is called from
> > mv88e6xxx_serdes_power_down context.
> > 
> > Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
> > 
> > Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
> > ---
> >  drivers/net/dsa/mv88e6xxx/serdes.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
> > index 55273013bfb5..33727439724a 100644
> > --- a/drivers/net/dsa/mv88e6xxx/serdes.c
> > +++ b/drivers/net/dsa/mv88e6xxx/serdes.c
> > @@ -1507,7 +1507,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
> >  			    bool on)
> >  {
> >  	u8 cmode = chip->ports[port].cmode;
> > -	int err;
> > +	int err = 0;
> >  
> >  	if (port != 0 && port != 9 && port != 10)
> >  		return -EOPNOTSUPP;  
> 
> Hi Marek
> 
> This warning likely comes from cmode not being a SERDES mode, and that
> is not handles in the switch statementing. Do we want an
> 
> default:
> 	err = EINVAL;
> 
> ?
> 
> 	Andrew

Hi Andrew,

currently all the .serdes_power() methods return 0 for non-serdes ports.
This is because the way it is written, these methods are not called if
there is not a serdes lane for a given port.

For this issue with err variable undefined, to fix it we should simply
set int err=0 at the beginning of mv88e6393x_serdes_power(), to make it
behave like other serdes_power() methods do in serdes.c.



But a refactor may be needed for serdes_power() methods, at least
because they are a little weird. But it should be unrelated to this fix.

In serdes.h we have static inline functions
  mv88e6xxx_serdes_power_up(chip, port, lane)
  mv88e6xxx_serdes_power_down(chip, port, lane)

  (These simply call the serdes_power() method of chip ops, with
   additional boolean argument to specify powerup/powerdown.
   Also for these we first need to determine lane for a port. If lane
   does not exists, these should not be called.)

In chip.c we have function
  mv88e6xxx_serdes_power(chip, port, on)
  
  (This finds if the port has a lane, and if so, calls, if on=true
   mv88e6xxx_serdes_power_up()
     from serdes.h, and then
   mv88e6xxx_serdes_irq_request()
     also from serdes.h

   and if on=false, calls _irq_free() & _serdes_power_down()
  )

So if I call
  mv88e6xxx_serdes_power(chip, port, true)
it goes
    mv88e6xxx_serdes_power_up(chip, port, lane)
      chip->info->ops->serdes_power(chip, port, lane, true)
so the `on` argument is used in some places, but in other places there
are two functions instead.

Which I find a little weird.

Marek

Re: [PATCH] net: dsa: mv88e6xxx: initialize return variable on declaration

[Jakub Kicinski]

On Mon, 6 Dec 2021 23:29:53 +0100 Marek Behún wrote:
> On Mon, 6 Dec 2021 14:21:03 +0100
> Andrew Lunn <andrew@lunn.ch> wrote:
> 
> > On Mon, Dec 06, 2021 at 04:32:19PM +0500, Ameer Hamza wrote:  
> > > Uninitialized err variable defined in mv88e6393x_serdes_power
> > > function may cause undefined behaviour if it is called from
> > > mv88e6xxx_serdes_power_down context.
> > > 
> > > Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
> > > 
> > > Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
> > > ---
> > >  drivers/net/dsa/mv88e6xxx/serdes.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
> > > index 55273013bfb5..33727439724a 100644
> > > --- a/drivers/net/dsa/mv88e6xxx/serdes.c
> > > +++ b/drivers/net/dsa/mv88e6xxx/serdes.c
> > > @@ -1507,7 +1507,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
> > >  			    bool on)
> > >  {
> > >  	u8 cmode = chip->ports[port].cmode;
> > > -	int err;
> > > +	int err = 0;
> > >  
> > >  	if (port != 0 && port != 9 && port != 10)
> > >  		return -EOPNOTSUPP;    
> > 
> > Hi Marek
> > 
> > This warning likely comes from cmode not being a SERDES mode, and that
> > is not handles in the switch statementing. Do we want an
> > 
> > default:
> > 	err = EINVAL;
> > 
> > ?
> 
> currently all the .serdes_power() methods return 0 for non-serdes ports.
> This is because the way it is written, these methods are not called if
> there is not a serdes lane for a given port.
> 
> For this issue with err variable undefined, to fix it we should simply
> set int err=0 at the beginning of mv88e6393x_serdes_power(), to make it
> behave like other serdes_power() methods do in serdes.c.

Any objections to using a default case in the switch statement, tho?
I agree with Andrew that default statement would make the reasoning
clearer than just setting the variable at the start of the function.

Re: [PATCH] net: dsa: mv88e6xxx: initialize return variable on declaration

[Marek Behún]

On Mon, 6 Dec 2021 16:25:10 -0800
Jakub Kicinski <kuba@kernel.org> wrote:

> On Mon, 6 Dec 2021 23:29:53 +0100 Marek Behún wrote:
> > On Mon, 6 Dec 2021 14:21:03 +0100
> > Andrew Lunn <andrew@lunn.ch> wrote:
> >   
> > > On Mon, Dec 06, 2021 at 04:32:19PM +0500, Ameer Hamza wrote:    
> > > > Uninitialized err variable defined in mv88e6393x_serdes_power
> > > > function may cause undefined behaviour if it is called from
> > > > mv88e6xxx_serdes_power_down context.
> > > > 
> > > > Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
> > > > 
> > > > Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
> > > > ---
> > > >  drivers/net/dsa/mv88e6xxx/serdes.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
> > > > index 55273013bfb5..33727439724a 100644
> > > > --- a/drivers/net/dsa/mv88e6xxx/serdes.c
> > > > +++ b/drivers/net/dsa/mv88e6xxx/serdes.c
> > > > @@ -1507,7 +1507,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
> > > >  			    bool on)
> > > >  {
> > > >  	u8 cmode = chip->ports[port].cmode;
> > > > -	int err;
> > > > +	int err = 0;
> > > >  
> > > >  	if (port != 0 && port != 9 && port != 10)
> > > >  		return -EOPNOTSUPP;      
> > > 
> > > Hi Marek
> > > 
> > > This warning likely comes from cmode not being a SERDES mode, and that
> > > is not handles in the switch statementing. Do we want an
> > > 
> > > default:
> > > 	err = EINVAL;
> > > 
> > > ?  
> > 
> > currently all the .serdes_power() methods return 0 for non-serdes ports.
> > This is because the way it is written, these methods are not called if
> > there is not a serdes lane for a given port.
> > 
> > For this issue with err variable undefined, to fix it we should simply
> > set int err=0 at the beginning of mv88e6393x_serdes_power(), to make it
> > behave like other serdes_power() methods do in serdes.c.  
> 
> Any objections to using a default case in the switch statement, tho?
> I agree with Andrew that default statement would make the reasoning
> clearer than just setting the variable at the start of the function.

No objection, just that it should be done for all the serdes_power()
methods in serdes.c.

Marek

[PATCH v2] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Ameer Hamza]

mv88e6390_serdes_power() and mv88e6393x_serdes_power() should return
with EINVAL error if cmode is undefined.

Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
---
 drivers/net/dsa/mv88e6xxx/serdes.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 33727439724a..f3dc1865f291 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -830,7 +830,7 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool up)
 {
 	u8 cmode = chip->ports[port].cmode;
-	int err = 0;
+	int err;
 
 	switch (cmode) {
 	case MV88E6XXX_PORT_STS_CMODE_SGMII:
@@ -842,6 +842,8 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 	case MV88E6XXX_PORT_STS_CMODE_RXAUI:
 		err = mv88e6390_serdes_power_10g(chip, lane, up);
 		break;
+	default:
+		return -EINVAL;
 	}
 
 	if (!err && up)
@@ -1507,7 +1509,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			    bool on)
 {
 	u8 cmode = chip->ports[port].cmode;
-	int err = 0;
+	int err;
 
 	if (port != 0 && port != 9 && port != 10)
 		return -EOPNOTSUPP;
@@ -1541,6 +1543,8 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 	case MV88E6393X_PORT_STS_CMODE_10GBASER:
 		err = mv88e6390_serdes_power_10g(chip, lane, on);
 		break;
+	default:
+		return -EINVAL;
 	}
 
 	if (err)
-- 
2.25.1

Re: [PATCH v2] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Ameer Hamza]

On Wed, Dec 08, 2021 at 07:04:13PM +0500, Ameer Hamza wrote:
> mv88e6390_serdes_power() and mv88e6393x_serdes_power() should return
> with EINVAL error if cmode is undefined.
> 
> Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
> ---
>  drivers/net/dsa/mv88e6xxx/serdes.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
> index 33727439724a..f3dc1865f291 100644
> --- a/drivers/net/dsa/mv88e6xxx/serdes.c
> +++ b/drivers/net/dsa/mv88e6xxx/serdes.c
> @@ -830,7 +830,7 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  			   bool up)
>  {
>  	u8 cmode = chip->ports[port].cmode;
> -	int err = 0;
> +	int err;
>  
>  	switch (cmode) {
>  	case MV88E6XXX_PORT_STS_CMODE_SGMII:
> @@ -842,6 +842,8 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  	case MV88E6XXX_PORT_STS_CMODE_RXAUI:
>  		err = mv88e6390_serdes_power_10g(chip, lane, up);
>  		break;
> +	default:
> +		return -EINVAL;
>  	}
>  
>  	if (!err && up)
> @@ -1507,7 +1509,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  			    bool on)
>  {
>  	u8 cmode = chip->ports[port].cmode;
> -	int err = 0;
> +	int err;
>  
>  	if (port != 0 && port != 9 && port != 10)
>  		return -EOPNOTSUPP;
> @@ -1541,6 +1543,8 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  	case MV88E6393X_PORT_STS_CMODE_10GBASER:
>  		err = mv88e6390_serdes_power_10g(chip, lane, on);
>  		break;
> +	default:
> +		return -EINVAL;
>  	}
>  
>  	if (err)
> -- 
> 2.25.1
>
Hi Marek,

I checked serdes.c and I found two methods mv88e6390_serdes_power() and
mv88e6390_serdes_power() that were not returning ENINVAL in case of
undefined cmode. Would be appreciated if  you can review the patch
please.

Best Regards,
Ameer Hamza.

Re: [PATCH v2] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Jakub Kicinski]

On Wed, 8 Dec 2021 19:09:57 +0500 Ameer Hamza wrote:
> I checked serdes.c and I found two methods mv88e6390_serdes_power() and
> mv88e6390_serdes_power() that were not returning ENINVAL in case of
> undefined cmode. Would be appreciated if  you can review the patch
> please.

A note for the future - please put more info into the commit 
message, it shouldn't be necessary to send a follow up email 
with the explanation.

Re: [PATCH v2] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Marek Behún]

On Wed,  8 Dec 2021 19:04:13 +0500
Ameer Hamza <amhamza.mgc@gmail.com> wrote:

> mv88e6390_serdes_power() and mv88e6393x_serdes_power() should return
> with EINVAL error if cmode is undefined.
> 
> Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
> ---
>  drivers/net/dsa/mv88e6xxx/serdes.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
> index 33727439724a..f3dc1865f291 100644
> --- a/drivers/net/dsa/mv88e6xxx/serdes.c
> +++ b/drivers/net/dsa/mv88e6xxx/serdes.c
> @@ -830,7 +830,7 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  			   bool up)
>  {
>  	u8 cmode = chip->ports[port].cmode;
> -	int err = 0;
> +	int err;
>  
>  	switch (cmode) {
>  	case MV88E6XXX_PORT_STS_CMODE_SGMII:
> @@ -842,6 +842,8 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  	case MV88E6XXX_PORT_STS_CMODE_RXAUI:
>  		err = mv88e6390_serdes_power_10g(chip, lane, up);
>  		break;
> +	default:
> +		return -EINVAL;
>  	}
>  
>  	if (!err && up)
> @@ -1507,7 +1509,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  			    bool on)
>  {
>  	u8 cmode = chip->ports[port].cmode;
> -	int err = 0;
> +	int err;
>  
>  	if (port != 0 && port != 9 && port != 10)
>  		return -EOPNOTSUPP;
> @@ -1541,6 +1543,8 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  	case MV88E6393X_PORT_STS_CMODE_10GBASER:
>  		err = mv88e6390_serdes_power_10g(chip, lane, on);
>  		break;
> +	default:
> +		return -EINVAL;
>  	}
>  
>  	if (err)

please make it err = -EINVAL instead of direct return, so that we can
check in the code after and handle the error case.

Marek

[PATCH v3] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Ameer Hamza]

Added default case to handle undefined cmode scenario in
mv88e6393x_serdes_power() and mv88e6393x_serdes_power() methods.

Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
---
Changes in v3:
make err = -EINVAL instead of direct return, so that we can
check in the code after and handle the error case.
---
 drivers/net/dsa/mv88e6xxx/serdes.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 33727439724a..2b05ead515cd 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -830,7 +830,7 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool up)
 {
 	u8 cmode = chip->ports[port].cmode;
-	int err = 0;
+	int err;
 
 	switch (cmode) {
 	case MV88E6XXX_PORT_STS_CMODE_SGMII:
@@ -842,6 +842,9 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 	case MV88E6XXX_PORT_STS_CMODE_RXAUI:
 		err = mv88e6390_serdes_power_10g(chip, lane, up);
 		break;
+	default:
+		err = -EINVAL;
+		break;
 	}
 
 	if (!err && up)
@@ -1507,7 +1510,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			    bool on)
 {
 	u8 cmode = chip->ports[port].cmode;
-	int err = 0;
+	int err;
 
 	if (port != 0 && port != 9 && port != 10)
 		return -EOPNOTSUPP;
@@ -1541,6 +1544,9 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 	case MV88E6393X_PORT_STS_CMODE_10GBASER:
 		err = mv88e6390_serdes_power_10g(chip, lane, on);
 		break;
+	default:
+		err = -EINVAL;
+		break;
 	}
 
 	if (err)
-- 
2.25.1

Re: [PATCH v3] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Marek Behún]

On Wed,  8 Dec 2021 20:58:09 +0500
Ameer Hamza <amhamza.mgc@gmail.com> wrote:

> Added default case to handle undefined cmode scenario in
> mv88e6393x_serdes_power() and mv88e6393x_serdes_power() methods.
> 
> Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
> ---

Reviewed-by: Marek Behún <kabel@kernel.org>

Re: [PATCH v3] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Jakub Kicinski]

On Wed,  8 Dec 2021 20:58:09 +0500 Ameer Hamza wrote:
> @@ -1507,7 +1510,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
>  			    bool on)
>  {
>  	u8 cmode = chip->ports[port].cmode;
> -	int err = 0;
> +	int err;
>  
>  	if (port != 0 && port != 9 && port != 10)
>  		return -EOPNOTSUPP;

This is on top of v1? It doesn't seem to apply, v1 was not merged.

Also can you please add Fixes tags?

Re: [PATCH v3] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Ameer Hamza]

On Wed, Dec 08, 2021 at 05:28:20PM -0800, Jakub Kicinski wrote:
> On Wed,  8 Dec 2021 20:58:09 +0500 Ameer Hamza wrote:
> > @@ -1507,7 +1510,7 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
> >  			    bool on)
> >  {
> >  	u8 cmode = chip->ports[port].cmode;
> > -	int err = 0;
> > +	int err;
> >  
> >  	if (port != 0 && port != 9 && port != 10)
> >  		return -EOPNOTSUPP;
> 
> This is on top of v1? It doesn't seem to apply, v1 was not merged.
Oh, sorry! Its not incremental but I think my repository was a
few commits old. Let me send the updated patch.

> Also can you please add Fixes tags?
Sure.

[PATCH v4] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Ameer Hamza]

Added default case to handle undefined cmode scenario in
mv88e6393x_serdes_power() and mv88e6393x_serdes_power() methods.

Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
Fixes: 21635d9203e1c (net: mvpp2: fix XDP rx queues registering)
Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
---
Changes in v4:
Added fix tag and synced patch with latest repo
---
 drivers/net/dsa/mv88e6xxx/serdes.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 55273013bfb5..2b05ead515cd 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -830,7 +830,7 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool up)
 {
 	u8 cmode = chip->ports[port].cmode;
-	int err = 0;
+	int err;
 
 	switch (cmode) {
 	case MV88E6XXX_PORT_STS_CMODE_SGMII:
@@ -842,6 +842,9 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 	case MV88E6XXX_PORT_STS_CMODE_RXAUI:
 		err = mv88e6390_serdes_power_10g(chip, lane, up);
 		break;
+	default:
+		err = -EINVAL;
+		break;
 	}
 
 	if (!err && up)
@@ -1541,6 +1544,9 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 	case MV88E6393X_PORT_STS_CMODE_10GBASER:
 		err = mv88e6390_serdes_power_10g(chip, lane, on);
 		break;
+	default:
+		err = -EINVAL;
+		break;
 	}
 
 	if (err)
-- 
2.25.1

[PATCH v4] net: dsa: mv88e6xxx: error handling for serdes_power functions

[Ameer Hamza]

Added default case to handle undefined cmode scenario in
mv88e6393x_serdes_power() and mv88e6393x_serdes_power() methods.

Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
Fixes: 21635d9203e1c (net: dsa: mv88e6xxx: Fix application of erratum 4.8 for 88E6393X)
Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
---
Changes in v4:
Correct commit message in fix tag
---
 drivers/net/dsa/mv88e6xxx/serdes.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 55273013bfb5..2b05ead515cd 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -830,7 +830,7 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 			   bool up)
 {
 	u8 cmode = chip->ports[port].cmode;
-	int err = 0;
+	int err;
 
 	switch (cmode) {
 	case MV88E6XXX_PORT_STS_CMODE_SGMII:
@@ -842,6 +842,9 @@ int mv88e6390_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 	case MV88E6XXX_PORT_STS_CMODE_RXAUI:
 		err = mv88e6390_serdes_power_10g(chip, lane, up);
 		break;
+	default:
+		err = -EINVAL;
+		break;
 	}
 
 	if (!err && up)
@@ -1541,6 +1544,9 @@ int mv88e6393x_serdes_power(struct mv88e6xxx_chip *chip, int port, int lane,
 	case MV88E6393X_PORT_STS_CMODE_10GBASER:
 		err = mv88e6390_serdes_power_10g(chip, lane, on);
 		break;
+	default:
+		err = -EINVAL;
+		break;
 	}
 
 	if (err)
-- 
2.25.1

Re: [PATCH v4] net: dsa: mv88e6xxx: error handling for serdes_power functions

[patchwork-bot+netdevbpf]

Hello:

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

On Thu,  9 Dec 2021 09:15:52 +0500 you wrote:
> Added default case to handle undefined cmode scenario in
> mv88e6393x_serdes_power() and mv88e6393x_serdes_power() methods.
> 
> Addresses-Coverity: 1494644 ("Uninitialized scalar variable")
> Fixes: 21635d9203e1c (net: dsa: mv88e6xxx: Fix application of erratum 4.8 for 88E6393X)
> Reviewed-by: Marek Behún <kabel@kernel.org>
> Signed-off-by: Ameer Hamza <amhamza.mgc@gmail.com>
> 
> [...]

Here is the summary with links:
  - [v4] net: dsa: mv88e6xxx: error handling for serdes_power functions
    https://git.kernel.org/netdev/net/c/0416e7af2369

You are awesome, thank you!
-- 
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