Re: [PATCH net-next v2 05/10] drivers: base: Add device_find_class()

2017-01-14 Thread Florian Fainelli 


On 01/13/2017 02:55 AM, David Laight wrote:
> From: Florian Fainelli
>> Sent: 12 January 2017 22:51
>> On 01/12/2017 01:21 PM, David Miller wrote:
>>> From: Florian Fainelli 
>>> Date: Wed, 11 Jan 2017 19:41:16 -0800
>>>
 Add a helper function to lookup a device reference given a class name.
 This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and
 make it more generic.
> ...
 +static int dev_is_class(struct device *dev, void *class)
>>>
>>> I know you are just moving code, but this class argumnet is a string
>>> and thus should be "char *" or even "const char *".
>>
>> Well, this is really so that we don't need to cast the arguments passed
>> to device_find_child(), which takes a void *data as well. If we made
>> that a const char *class, we'd get warnings that look like these:
>>
>> drivers/base/core.c: In function 'device_find_class':
>> drivers/base/core.c:2083:2: warning: passing argument 2 of
>> 'device_find_child' discards 'const' qualifier from pointer target type
>> [enabled by default]
>>   return device_find_child(parent, class, dev_is_class);
>>   ^
>> drivers/base/core.c:2050:16: note: expected 'void *' but argument is of
>> type 'const char *'
>>  struct device *device_find_child(struct device *parent, void *data,
>> ^
> ...
> 
> Maybe device_find_child() needs changing to take 'const void *' ?

As a separate patch set, sure, I will add that to my TODO. Thanks!
-- 
Florian

RE: [PATCH net-next v2 05/10] drivers: base: Add device_find_class()

2017-01-13 Thread David Laight 
From: Florian Fainelli
> Sent: 12 January 2017 22:51
> On 01/12/2017 01:21 PM, David Miller wrote:
> > From: Florian Fainelli 
> > Date: Wed, 11 Jan 2017 19:41:16 -0800
> >
> >> Add a helper function to lookup a device reference given a class name.
> >> This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and
> >> make it more generic.
...
> >> +static int dev_is_class(struct device *dev, void *class)
> >
> > I know you are just moving code, but this class argumnet is a string
> > and thus should be "char *" or even "const char *".
> 
> Well, this is really so that we don't need to cast the arguments passed
> to device_find_child(), which takes a void *data as well. If we made
> that a const char *class, we'd get warnings that look like these:
> 
> drivers/base/core.c: In function 'device_find_class':
> drivers/base/core.c:2083:2: warning: passing argument 2 of
> 'device_find_child' discards 'const' qualifier from pointer target type
> [enabled by default]
>   return device_find_child(parent, class, dev_is_class);
>   ^
> drivers/base/core.c:2050:16: note: expected 'void *' but argument is of
> type 'const char *'
>  struct device *device_find_child(struct device *parent, void *data,
> ^
...

Maybe device_find_child() needs changing to take 'const void *' ?

David

Re: [PATCH net-next v2 05/10] drivers: base: Add device_find_class()

2017-01-12 Thread David Miller 
From: Florian Fainelli 
Date: Thu, 12 Jan 2017 14:50:39 -0800

> Well, this is really so that we don't need to cast the arguments passed
> to device_find_child(), which takes a void *data as well.

Aha, I didn't catch that, my bad.

Re: [PATCH net-next v2 05/10] drivers: base: Add device_find_class()

2017-01-12 Thread Florian Fainelli 
On 01/12/2017 01:21 PM, David Miller wrote:
> From: Florian Fainelli 
> Date: Wed, 11 Jan 2017 19:41:16 -0800
> 
>> Add a helper function to lookup a device reference given a class name.
>> This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and
>> make it more generic.
>>
>> Signed-off-by: Florian Fainelli 
>> ---
>>  drivers/base/core.c| 19 +++
>>  include/linux/device.h |  1 +
>>  2 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/base/core.c b/drivers/base/core.c
>> index 020ea7f05520..3dd6047c10d8 100644
>> --- a/drivers/base/core.c
>> +++ b/drivers/base/core.c
>> @@ -2065,6 +2065,25 @@ struct device *device_find_child(struct device 
>> *parent, void *data,
>>  }
>>  EXPORT_SYMBOL_GPL(device_find_child);
>>  
>> +static int dev_is_class(struct device *dev, void *class)
> 
> I know you are just moving code, but this class argumnet is a string
> and thus should be "char *" or even "const char *".

Well, this is really so that we don't need to cast the arguments passed
to device_find_child(), which takes a void *data as well. If we made
that a const char *class, we'd get warnings that look like these:

drivers/base/core.c: In function 'device_find_class':
drivers/base/core.c:2083:2: warning: passing argument 2 of
'device_find_child' discards 'const' qualifier from pointer target type
[enabled by default]
  return device_find_child(parent, class, dev_is_class);
  ^
drivers/base/core.c:2050:16: note: expected 'void *' but argument is of
type 'const char *'
 struct device *device_find_child(struct device *parent, void *data,
^
drivers/base/core.c:2083:2: warning: passing argument 3 of
'device_find_child' from incompatible pointer type [enabled by default]
  return device_find_child(parent, class, dev_is_class);
  ^
drivers/base/core.c:2050:16: note: expected 'int (*)(struct device *,
void *)' but argument is of type 'int (*)(struct device *, const char *)'
 struct device *device_find_child(struct device *parent, void *data,
^

-- 
Florian

Re: [PATCH net-next v2 05/10] drivers: base: Add device_find_class()

2017-01-12 Thread David Miller 
From: Florian Fainelli 
Date: Wed, 11 Jan 2017 19:41:16 -0800

> Add a helper function to lookup a device reference given a class name.
> This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and
> make it more generic.
> 
> Signed-off-by: Florian Fainelli 
> ---
>  drivers/base/core.c| 19 +++
>  include/linux/device.h |  1 +
>  2 files changed, 20 insertions(+)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 020ea7f05520..3dd6047c10d8 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -2065,6 +2065,25 @@ struct device *device_find_child(struct device 
> *parent, void *data,
>  }
>  EXPORT_SYMBOL_GPL(device_find_child);
>  
> +static int dev_is_class(struct device *dev, void *class)

I know you are just moving code, but this class argumnet is a string
and thus should be "char *" or even "const char *".

[PATCH net-next v2 05/10] drivers: base: Add device_find_class()

2017-01-11 Thread Florian Fainelli 
Add a helper function to lookup a device reference given a class name.
This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and
make it more generic.

Signed-off-by: Florian Fainelli 
---
 drivers/base/core.c| 19 +++
 include/linux/device.h |  1 +
 2 files changed, 20 insertions(+)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 020ea7f05520..3dd6047c10d8 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2065,6 +2065,25 @@ struct device *device_find_child(struct device *parent, 
void *data,
 }
 EXPORT_SYMBOL_GPL(device_find_child);
 
+static int dev_is_class(struct device *dev, void *class)
+{
+   if (dev->class != NULL && !strcmp(dev->class->name, class))
+   return 1;
+
+   return 0;
+}
+
+struct device *device_find_class(struct device *parent, char *class)
+{
+   if (dev_is_class(parent, class)) {
+   get_device(parent);
+   return parent;
+   }
+
+   return device_find_child(parent, class, dev_is_class);
+}
+EXPORT_SYMBOL_GPL(device_find_class);
+
 int __init devices_init(void)
 {
devices_kset = kset_create_and_add("devices", _uevent_ops, NULL);
diff --git a/include/linux/device.h b/include/linux/device.h
index 491b4c0ca633..8d37f5ecb972 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1120,6 +1120,7 @@ extern int device_for_each_child_reverse(struct device 
*dev, void *data,
 int (*fn)(struct device *dev, void *data));
 extern struct device *device_find_child(struct device *dev, void *data,
int (*match)(struct device *dev, void *data));
+extern struct device *device_find_class(struct device *parent, char *class);
 extern int device_rename(struct device *dev, const char *new_name);
 extern int device_move(struct device *dev, struct device *new_parent,
   enum dpm_order dpm_order);
-- 
2.9.3