[PATCH v4 4/4] phytec: phycore_imx8mp: override env_get_location

[Marek Vasut]

On 2/1/22 10:09, Tommaso Merciai wrote:
> On Tue, Feb 01, 2022 at 04:16:52AM +0100, Marek Vasut wrote:
>> On 1/31/22 23:15, Tommaso Merciai wrote:
>>> On Mon, Jan 31, 2022 at 06:03:58PM +0100, Marek Vasut wrote:
>>>> On 1/31/22 17:58, Tommaso Merciai wrote:
>>>>> Override env_get_location function at board level, previously dropped
>>>>> down from arch/arm/mach-imx/imx8m/soc.c
>>>>>
>>>>> References:
>>>>>     - commit 98af80d3c969e69a1b8ce98bb20e5ad844022da2
>>>>>
>>>>> Signed-off-by: Tommaso Merciai <tommaso.merciai at amarulasolutions.com>
>>>>> ---
>>>>>     board/phytec/phycore_imx8mp/phycore-imx8mp.c | 33 ++++++++++++++++++++
>>>>>     1 file changed, 33 insertions(+)
>>>>>
>>>>> diff --git a/board/phytec/phycore_imx8mp/phycore-imx8mp.c b/board/phytec/phycore_imx8mp/phycore-imx8mp.c
>>>>> index a8f0821437..05926eefa3 100644
>>>>> --- a/board/phytec/phycore_imx8mp/phycore-imx8mp.c
>>>>> +++ b/board/phytec/phycore_imx8mp/phycore-imx8mp.c
>>>>> @@ -11,9 +11,42 @@
>>>>>     #include <asm/mach-imx/boot_mode.h>
>>>>>     #include <env.h>
>>>>>     #include <miiphy.h>
>>>>> +#include <env_internal.h>
>>>>>     DECLARE_GLOBAL_DATA_PTR;
>>>>> +enum env_location env_get_location(enum env_operation op, int prio)
>>>>> +{
>>>>
>>>> Why don't you just turn this into default __weak function and override it on
>>>> board level when it is really needed to be overridden ?
>>>
>>> Hi Marek,
>>> env_get_location is already declared as __weak, check env/env.c. We
>>> can't override it 2 times.
>>
>> Oh, it is this problem with missing ability to define multiple levels of
>> symbol strength.
>>
>> __weak enum env_location arch_env_get_location(enum env_operation op, int
>> prio)
>> {
>>          if (prio >= ARRAY_SIZE(env_locations))
>>                  return ENVL_UNKNOWN;
>>
>>          return env_locations[prio];
>> }
>>
>> __weak enum env_location board_env_get_location(enum env_operation op, int
>> prio)
>> {
>> 	return arch_env_get_location(op, prio);
>> }
>>
>> __weak enum env_location env_get_location(enum env_operation op, int prio)
>> {
>> 	return board_env_get_location(op, prio);
>> }
>>
>> By default, the compiler will optimize it all out. If you have arch-specific
>> default (like imx does), implement arch_env_get_location(), if you have even
>> board-specific default (like your board likely does), implement
>> board_env_get_location(), if you need to override both, then override
>> env_get_location() (unlikely).
>>
>> This is also inline with all the other arch_*() and board_*() functions we
>> have, and you won't have much duplication either.
> 
> Hi Marek,
> Thanks for the tips, then if I understand correctly, your idea is: use:
> 
> arch_env_get_location in (soc.c)
> 
> In this way imx8m users can override this function at board level using:
> 
> board_env_get_location
> 
> right?

Yes, I think that is the most flexible way with least duplication.