Re: [PATCH v2 5/5] configs: am335x_evm: Fix BeagleBone Green DTB selection

[Lokesh Vutla <lokeshvutla@ti.com>]

On 20/07/21 1:49 pm, Paul Barker wrote:
> On Tue, 13 Jul 2021 11:59:06 +0530
> Lokesh Vutla <lokeshvutla@ti.com> wrote:
> 
>> On 13/07/21 1:44 am, Paul Barker wrote:
>>> The function board_is_bone_lt() returns true for the BeagleBone Green,
>>> the BeagleBone Enhanced and the BeagleBone Black. Therefore when
>>> selecting which devicetree to use we must ensure that the more specific
>>> functions board_is_bbg1() and board_is_bben() are checked first
>>> otherwise all three devices would end up using the am335x-boneblack
>>> devicetree. This can be achieved by placing the relevant devicetree
>>> names (am335x-sancloud-bbe and am335x-bonegreen) before am335x-boneblack
>>> in CONFIG_OF_LIST.  
>>
>> Such restrictions should be handled inside board_fit_config_name_match() and
>> hiden from user configuration. Can you update the board_fit_config_name_match()
>> instead of updating defconfig?
> 
> Hi Lokesh,
> 
> Apologies for the late reply, I lost most of last week due to illness.
> 
> I first attempted to fix this by changing the order of things in
> `board_fit_config_name_match` but it had no effect. Looking at
> `fit_find_config_node` in `common/common_fit.c`, we loop through the
> list of dtbs and check each one in turn for a match. So to move
> am335x-bonegreen ahead of am335x-boneblack we need to change the order
> in which the dtbs are checked in `fit_find_config_node`. The simplest
> way I could find to do that is to change the order of the names in
> CONFIG_OF_LIST.

ahh..ok got it. But still such constraints in config file is most likely will
not be maintained in future when someone touching the config. Because not
everyone knows this.

Is it possible to create a new macro which is true only for bbb and use it
instead in board_fit_config_name_match?

Thanks and reagrds,
Lokesh

> 
> Thanks,
>