[PATCH 0/3] [media] cx231xx: cleanup i2c adapter handling

[PATCH 0/3] [media] cx231xx: cleanup i2c adapter handling

[Peter Rosin]

Hi!

This seems like fairly straight forward cleanups/bugfixes. I don't
have the hardware and found the issues by reading code while doing
other things. So, it builds for me, but it's untested.

1/3 changes behavior on failure, but I think it's the right thing
to do. If it isn't for some reason, then the current code is crap
anyway, because as-is it compares with a value that is always zero
meaning that the entire "if (0 != bus->i2c_rc)"-clause with its
dev_warn can be removed from cx231xx_i2c_register.

Cheers,
Peter

Peter Rosin (3):
  [media] cx231xx: fail probe if i2c_add_adapter fails
  [media] cx231xx: drop return value of cx231xx_i2c_unregister
  [media] cx231xx: only unregister successfully registered i2c adapters

 drivers/media/usb/cx231xx/cx231xx-core.c | 3 +++
 drivers/media/usb/cx231xx/cx231xx-i2c.c  | 8 ++++----
 drivers/media/usb/cx231xx/cx231xx.h      | 4 ++--
 3 files changed, 9 insertions(+), 6 deletions(-)

-- 
2.11.0

[PATCH 1/3] [media] cx231xx: fail probe if i2c_add_adapter fails

[Peter Rosin]

While at it, change the type of the previously always-zero i2c_rc
member to int, matching the returned type from i2c_add_adapter.

Signed-off-by: Peter Rosin <peda@axentia.se>
---
 drivers/media/usb/cx231xx/cx231xx-i2c.c | 2 +-
 drivers/media/usb/cx231xx/cx231xx.h     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/cx231xx/cx231xx-i2c.c b/drivers/media/usb/cx231xx/cx231xx-i2c.c
index 8d95b1154e12..3a0c45ffd40f 100644
--- a/drivers/media/usb/cx231xx/cx231xx-i2c.c
+++ b/drivers/media/usb/cx231xx/cx231xx-i2c.c
@@ -538,7 +538,7 @@ int cx231xx_i2c_register(struct cx231xx_i2c *bus)
 
 	bus->i2c_adap.algo_data = bus;
 	i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
-	i2c_add_adapter(&bus->i2c_adap);
+	bus->i2c_rc = i2c_add_adapter(&bus->i2c_adap);
 
 	if (0 != bus->i2c_rc)
 		dev_warn(dev->dev,
diff --git a/drivers/media/usb/cx231xx/cx231xx.h b/drivers/media/usb/cx231xx/cx231xx.h
index 986c64ba5b56..27ee035f9f84 100644
--- a/drivers/media/usb/cx231xx/cx231xx.h
+++ b/drivers/media/usb/cx231xx/cx231xx.h
@@ -476,7 +476,7 @@ struct cx231xx_i2c {
 
 	/* i2c i/o */
 	struct i2c_adapter i2c_adap;
-	u32 i2c_rc;
+	int i2c_rc;
 
 	/* different settings for each bus */
 	u8 i2c_period;
-- 
2.11.0

[PATCH 2/3] [media] cx231xx: drop return value of cx231xx_i2c_unregister

[Peter Rosin]

Noone cares anyway.

Signed-off-by: Peter Rosin <peda@axentia.se>
---
 drivers/media/usb/cx231xx/cx231xx-i2c.c | 3 +--
 drivers/media/usb/cx231xx/cx231xx.h     | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/media/usb/cx231xx/cx231xx-i2c.c b/drivers/media/usb/cx231xx/cx231xx-i2c.c
index 3a0c45ffd40f..3e49517cb5e0 100644
--- a/drivers/media/usb/cx231xx/cx231xx-i2c.c
+++ b/drivers/media/usb/cx231xx/cx231xx-i2c.c
@@ -551,10 +551,9 @@ int cx231xx_i2c_register(struct cx231xx_i2c *bus)
  * cx231xx_i2c_unregister()
  * unregister i2c_bus
  */
-int cx231xx_i2c_unregister(struct cx231xx_i2c *bus)
+void cx231xx_i2c_unregister(struct cx231xx_i2c *bus)
 {
 	i2c_del_adapter(&bus->i2c_adap);
-	return 0;
 }
 
 /*
diff --git a/drivers/media/usb/cx231xx/cx231xx.h b/drivers/media/usb/cx231xx/cx231xx.h
index 27ee035f9f84..72d5937a087e 100644
--- a/drivers/media/usb/cx231xx/cx231xx.h
+++ b/drivers/media/usb/cx231xx/cx231xx.h
@@ -762,7 +762,7 @@ int cx231xx_reset_analog_tuner(struct cx231xx *dev);
 /* Provided by cx231xx-i2c.c */
 void cx231xx_do_i2c_scan(struct cx231xx *dev, int i2c_port);
 int cx231xx_i2c_register(struct cx231xx_i2c *bus);
-int cx231xx_i2c_unregister(struct cx231xx_i2c *bus);
+void cx231xx_i2c_unregister(struct cx231xx_i2c *bus);
 int cx231xx_i2c_mux_create(struct cx231xx *dev);
 int cx231xx_i2c_mux_register(struct cx231xx *dev, int mux_no);
 void cx231xx_i2c_mux_unregister(struct cx231xx *dev);
-- 
2.11.0

[PATCH 3/3] [media] cx231xx: only unregister successfully registered i2c adapters

[Peter Rosin]

This prevents potentially scary debug messages from the i2c core.

Signed-off-by: Peter Rosin <peda@axentia.se>
---
 drivers/media/usb/cx231xx/cx231xx-core.c | 3 +++
 drivers/media/usb/cx231xx/cx231xx-i2c.c  | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/cx231xx/cx231xx-core.c b/drivers/media/usb/cx231xx/cx231xx-core.c
index 46646ecd2dbc..f372ad3917a8 100644
--- a/drivers/media/usb/cx231xx/cx231xx-core.c
+++ b/drivers/media/usb/cx231xx/cx231xx-core.c
@@ -1311,6 +1311,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
 	dev->i2c_bus[0].i2c_period = I2C_SPEED_100K;	/* 100 KHz */
 	dev->i2c_bus[0].i2c_nostop = 0;
 	dev->i2c_bus[0].i2c_reserve = 0;
+	dev->i2c_bus[0].i2c_rc = -ENODEV;
 
 	/* External Master 2 Bus */
 	dev->i2c_bus[1].nr = 1;
@@ -1318,6 +1319,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
 	dev->i2c_bus[1].i2c_period = I2C_SPEED_100K;	/* 100 KHz */
 	dev->i2c_bus[1].i2c_nostop = 0;
 	dev->i2c_bus[1].i2c_reserve = 0;
+	dev->i2c_bus[1].i2c_rc = -ENODEV;
 
 	/* Internal Master 3 Bus */
 	dev->i2c_bus[2].nr = 2;
@@ -1325,6 +1327,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
 	dev->i2c_bus[2].i2c_period = I2C_SPEED_100K;	/* 100kHz */
 	dev->i2c_bus[2].i2c_nostop = 0;
 	dev->i2c_bus[2].i2c_reserve = 0;
+	dev->i2c_bus[2].i2c_rc = -ENODEV;
 
 	/* register I2C buses */
 	errCode = cx231xx_i2c_register(&dev->i2c_bus[0]);
diff --git a/drivers/media/usb/cx231xx/cx231xx-i2c.c b/drivers/media/usb/cx231xx/cx231xx-i2c.c
index 3e49517cb5e0..8ce6b815d16d 100644
--- a/drivers/media/usb/cx231xx/cx231xx-i2c.c
+++ b/drivers/media/usb/cx231xx/cx231xx-i2c.c
@@ -553,7 +553,8 @@ int cx231xx_i2c_register(struct cx231xx_i2c *bus)
  */
 void cx231xx_i2c_unregister(struct cx231xx_i2c *bus)
 {
-	i2c_del_adapter(&bus->i2c_adap);
+	if (!bus->i2c_rc)
+		i2c_del_adapter(&bus->i2c_adap);
 }
 
 /*
-- 
2.11.0

Re: [PATCH 3/3] [media] cx231xx: only unregister successfully registered i2c adapters

[Mauro Carvalho Chehab]

Em Mon, 31 Jul 2017 15:38:52 +0200
Peter Rosin <peda@axentia.se> escreveu:

> This prevents potentially scary debug messages from the i2c core.
> 
> Signed-off-by: Peter Rosin <peda@axentia.se>
> ---
>  drivers/media/usb/cx231xx/cx231xx-core.c | 3 +++
>  drivers/media/usb/cx231xx/cx231xx-i2c.c  | 3 ++-
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/usb/cx231xx/cx231xx-core.c b/drivers/media/usb/cx231xx/cx231xx-core.c
> index 46646ecd2dbc..f372ad3917a8 100644
> --- a/drivers/media/usb/cx231xx/cx231xx-core.c
> +++ b/drivers/media/usb/cx231xx/cx231xx-core.c
> @@ -1311,6 +1311,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
>  	dev->i2c_bus[0].i2c_period = I2C_SPEED_100K;	/* 100 KHz */
>  	dev->i2c_bus[0].i2c_nostop = 0;
>  	dev->i2c_bus[0].i2c_reserve = 0;
> +	dev->i2c_bus[0].i2c_rc = -ENODEV;
>  
>  	/* External Master 2 Bus */
>  	dev->i2c_bus[1].nr = 1;
> @@ -1318,6 +1319,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
>  	dev->i2c_bus[1].i2c_period = I2C_SPEED_100K;	/* 100 KHz */
>  	dev->i2c_bus[1].i2c_nostop = 0;
>  	dev->i2c_bus[1].i2c_reserve = 0;
> +	dev->i2c_bus[1].i2c_rc = -ENODEV;
>  
>  	/* Internal Master 3 Bus */
>  	dev->i2c_bus[2].nr = 2;
> @@ -1325,6 +1327,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
>  	dev->i2c_bus[2].i2c_period = I2C_SPEED_100K;	/* 100kHz */
>  	dev->i2c_bus[2].i2c_nostop = 0;
>  	dev->i2c_bus[2].i2c_reserve = 0;
> +	dev->i2c_bus[2].i2c_rc = -ENODEV;
>  
>  	/* register I2C buses */
>  	errCode = cx231xx_i2c_register(&dev->i2c_bus[0]);
> diff --git a/drivers/media/usb/cx231xx/cx231xx-i2c.c b/drivers/media/usb/cx231xx/cx231xx-i2c.c
> index 3e49517cb5e0..8ce6b815d16d 100644
> --- a/drivers/media/usb/cx231xx/cx231xx-i2c.c
> +++ b/drivers/media/usb/cx231xx/cx231xx-i2c.c
> @@ -553,7 +553,8 @@ int cx231xx_i2c_register(struct cx231xx_i2c *bus)
>   */
>  void cx231xx_i2c_unregister(struct cx231xx_i2c *bus)
>  {
> -	i2c_del_adapter(&bus->i2c_adap);
> +	if (!bus->i2c_rc)
> +		i2c_del_adapter(&bus->i2c_adap);

That doesn't sound right. what happens if i2c_rc is 1 or 2?

IMHO, the right would would be, instead:

	if (bus->i2c_rc >= 0)
		i2c_del_adapter(&bus->i2c_adap);

Regards

Thanks,
Mauro

Re: [PATCH 3/3] [media] cx231xx: only unregister successfully registered i2c adapters

[Peter Rosin]

On 2017-08-09 16:27, Mauro Carvalho Chehab wrote:
> Em Mon, 31 Jul 2017 15:38:52 +0200
> Peter Rosin <peda@axentia.se> escreveu:
> 
>> This prevents potentially scary debug messages from the i2c core.
>>
>> Signed-off-by: Peter Rosin <peda@axentia.se>
>> ---
>>  drivers/media/usb/cx231xx/cx231xx-core.c | 3 +++
>>  drivers/media/usb/cx231xx/cx231xx-i2c.c  | 3 ++-
>>  2 files changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/usb/cx231xx/cx231xx-core.c b/drivers/media/usb/cx231xx/cx231xx-core.c
>> index 46646ecd2dbc..f372ad3917a8 100644
>> --- a/drivers/media/usb/cx231xx/cx231xx-core.c
>> +++ b/drivers/media/usb/cx231xx/cx231xx-core.c
>> @@ -1311,6 +1311,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
>>  	dev->i2c_bus[0].i2c_period = I2C_SPEED_100K;	/* 100 KHz */
>>  	dev->i2c_bus[0].i2c_nostop = 0;
>>  	dev->i2c_bus[0].i2c_reserve = 0;
>> +	dev->i2c_bus[0].i2c_rc = -ENODEV;
>>  
>>  	/* External Master 2 Bus */
>>  	dev->i2c_bus[1].nr = 1;
>> @@ -1318,6 +1319,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
>>  	dev->i2c_bus[1].i2c_period = I2C_SPEED_100K;	/* 100 KHz */
>>  	dev->i2c_bus[1].i2c_nostop = 0;
>>  	dev->i2c_bus[1].i2c_reserve = 0;
>> +	dev->i2c_bus[1].i2c_rc = -ENODEV;
>>  
>>  	/* Internal Master 3 Bus */
>>  	dev->i2c_bus[2].nr = 2;
>> @@ -1325,6 +1327,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
>>  	dev->i2c_bus[2].i2c_period = I2C_SPEED_100K;	/* 100kHz */
>>  	dev->i2c_bus[2].i2c_nostop = 0;
>>  	dev->i2c_bus[2].i2c_reserve = 0;
>> +	dev->i2c_bus[2].i2c_rc = -ENODEV;
>>  
>>  	/* register I2C buses */
>>  	errCode = cx231xx_i2c_register(&dev->i2c_bus[0]);
>> diff --git a/drivers/media/usb/cx231xx/cx231xx-i2c.c b/drivers/media/usb/cx231xx/cx231xx-i2c.c
>> index 3e49517cb5e0..8ce6b815d16d 100644
>> --- a/drivers/media/usb/cx231xx/cx231xx-i2c.c
>> +++ b/drivers/media/usb/cx231xx/cx231xx-i2c.c
>> @@ -553,7 +553,8 @@ int cx231xx_i2c_register(struct cx231xx_i2c *bus)
>>   */
>>  void cx231xx_i2c_unregister(struct cx231xx_i2c *bus)
>>  {
>> -	i2c_del_adapter(&bus->i2c_adap);
>> +	if (!bus->i2c_rc)
>> +		i2c_del_adapter(&bus->i2c_adap);
> 
> That doesn't sound right. what happens if i2c_rc is 1 or 2?
> 
> IMHO, the right would would be, instead:
> 
> 	if (bus->i2c_rc >= 0)
> 		i2c_del_adapter(&bus->i2c_adap);

In theory, yes. But in practice i2c_add_adapter never returns >0, and is
also documented so.

Let me know if you still want an update. In that case I'll also fix the
precedent present in the context of patch 1/3, i.e.

	if (0 != bus->i2c_rc)
		...

Cheers,
peda

Re: [PATCH 3/3] [media] cx231xx: only unregister successfully registered i2c adapters

[Mauro Carvalho Chehab]

Em Wed, 9 Aug 2017 16:43:03 +0200
Peter Rosin <peda@axentia.se> escreveu:

> On 2017-08-09 16:27, Mauro Carvalho Chehab wrote:
> > Em Mon, 31 Jul 2017 15:38:52 +0200
> > Peter Rosin <peda@axentia.se> escreveu:
> >   
> >> This prevents potentially scary debug messages from the i2c core.
> >>
> >> Signed-off-by: Peter Rosin <peda@axentia.se>
> >> ---
> >>  drivers/media/usb/cx231xx/cx231xx-core.c | 3 +++
> >>  drivers/media/usb/cx231xx/cx231xx-i2c.c  | 3 ++-
> >>  2 files changed, 5 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/media/usb/cx231xx/cx231xx-core.c b/drivers/media/usb/cx231xx/cx231xx-core.c
> >> index 46646ecd2dbc..f372ad3917a8 100644
> >> --- a/drivers/media/usb/cx231xx/cx231xx-core.c
> >> +++ b/drivers/media/usb/cx231xx/cx231xx-core.c
> >> @@ -1311,6 +1311,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
> >>  	dev->i2c_bus[0].i2c_period = I2C_SPEED_100K;	/* 100 KHz */
> >>  	dev->i2c_bus[0].i2c_nostop = 0;
> >>  	dev->i2c_bus[0].i2c_reserve = 0;
> >> +	dev->i2c_bus[0].i2c_rc = -ENODEV;
> >>  
> >>  	/* External Master 2 Bus */
> >>  	dev->i2c_bus[1].nr = 1;
> >> @@ -1318,6 +1319,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
> >>  	dev->i2c_bus[1].i2c_period = I2C_SPEED_100K;	/* 100 KHz */
> >>  	dev->i2c_bus[1].i2c_nostop = 0;
> >>  	dev->i2c_bus[1].i2c_reserve = 0;
> >> +	dev->i2c_bus[1].i2c_rc = -ENODEV;
> >>  
> >>  	/* Internal Master 3 Bus */
> >>  	dev->i2c_bus[2].nr = 2;
> >> @@ -1325,6 +1327,7 @@ int cx231xx_dev_init(struct cx231xx *dev)
> >>  	dev->i2c_bus[2].i2c_period = I2C_SPEED_100K;	/* 100kHz */
> >>  	dev->i2c_bus[2].i2c_nostop = 0;
> >>  	dev->i2c_bus[2].i2c_reserve = 0;
> >> +	dev->i2c_bus[2].i2c_rc = -ENODEV;
> >>  
> >>  	/* register I2C buses */
> >>  	errCode = cx231xx_i2c_register(&dev->i2c_bus[0]);
> >> diff --git a/drivers/media/usb/cx231xx/cx231xx-i2c.c b/drivers/media/usb/cx231xx/cx231xx-i2c.c
> >> index 3e49517cb5e0..8ce6b815d16d 100644
> >> --- a/drivers/media/usb/cx231xx/cx231xx-i2c.c
> >> +++ b/drivers/media/usb/cx231xx/cx231xx-i2c.c
> >> @@ -553,7 +553,8 @@ int cx231xx_i2c_register(struct cx231xx_i2c *bus)
> >>   */
> >>  void cx231xx_i2c_unregister(struct cx231xx_i2c *bus)
> >>  {
> >> -	i2c_del_adapter(&bus->i2c_adap);
> >> +	if (!bus->i2c_rc)
> >> +		i2c_del_adapter(&bus->i2c_adap);  
> > 
> > That doesn't sound right. what happens if i2c_rc is 1 or 2?
> > 
> > IMHO, the right would would be, instead:
> > 
> > 	if (bus->i2c_rc >= 0)
> > 		i2c_del_adapter(&bus->i2c_adap);  
> 
> In theory, yes. But in practice i2c_add_adapter never returns >0, and is
> also documented so.

Good point. Just applied the patch.
> 
> Let me know if you still want an update. In that case I'll also fix the
> precedent present in the context of patch 1/3, i.e.
> 
> 	if (0 != bus->i2c_rc)
> 		...
> 
> Cheers,
> peda



Thanks,
Mauro