Re: [PATCH next 3/3] ipvlan: Introduce l3s mode

[David Miller <davem@davemloft.net>]

From: David Ahern <dsa@cumulusnetworks.com>
Date: Sat, 10 Sep 2016 10:25:27 -0600

> On 9/9/16 4:46 PM, Mahesh Bandewar (महेश बंडेवार) wrote:
>> On Fri, Sep 9, 2016 at 3:26 PM, David Ahern <dsa@cumulusnetworks.com> wrote:
>>> On 9/9/16 3:53 PM, Mahesh Bandewar wrote:
>>>> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
>>>> index 0c5415b05ea9..95edd1737ab5 100644
>>>> --- a/drivers/net/Kconfig
>>>> +++ b/drivers/net/Kconfig
>>>> @@ -149,6 +149,7 @@ config IPVLAN
>>>>      tristate "IP-VLAN support"
>>>>      depends on INET
>>>>      depends on IPV6
>>>> +    select NET_L3_MASTER_DEV
>>>
>>> depends on instead of select?
>> 
>> The kbuild/kconfig-language.txt suggests that for "depends on" the
>> option _must_ be selected otherwise menuconfig wont even present the
>> dependent option while select positively sets the option.
> 
> understood. VRF driver uses 'depends on'

Select is for things that are largely invisible to the user.  It is more of
a brute force tool that has several limitations.  For one, it doesn't
recursively apply dependencies of the thing you selected.  This makes it
quite trivial to create situations where you select X but it actually
can't work because it's "depend" statements aren't satistfied.

Depend is really the thing you ought to use, and yes this means that the
user has to know to enable the thing you depend upon to make your feature
available.  But that's just how it works.