[PATCH v4 1/5] efi: stub: Define debug uart functions only if CONFIG_DEBUG_UART is enabled

[Quentin Schulz]

On 5/19/25 5:43 PM, Tom Rini wrote:
> On Mon, May 19, 2025 at 05:09:07PM +0200, Quentin Schulz wrote:
>> Hi Tom,
>>
>> On 5/19/25 4:48 PM, Tom Rini wrote:
>>> On Thu, May 15, 2025 at 05:55:44PM +0200, Lukasz Czechowski wrote:
>>>> Initialize the debug uart only in case CONFIG_DEBUG_UART is
>>>> enabled. The _debug_uart_putc is used internally by debug uart
>>>> functions, so it must be also included inside #ifdef block,
>>>> otherwise it will cause compilation warnings.
>>>>
>>>> Signed-off-by: Lukasz Czechowski <lukasz.czechowski at thaumatec.com>
>>>> ---
>>>>    lib/efi/efi_stub.c | 2 ++
>>>>    1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/lib/efi/efi_stub.c b/lib/efi/efi_stub.c
>>>> index 40fc29d9adf7..5172cd78a7c0 100644
>>>> --- a/lib/efi/efi_stub.c
>>>> +++ b/lib/efi/efi_stub.c
>>>> @@ -83,12 +83,14 @@ void puts(const char *str)
>>>>    		putc(*str++);
>>>>    }
>>>> +#ifdef CONFIG_DEBUG_UART
>>>>    static void _debug_uart_putc(int ch)
>>>>    {
>>>>    	putc(ch);
>>>>    }
>>>>    DEBUG_UART_FUNCS
>>>> +#endif
>>>>    void *memcpy(void *dest, const void *src, size_t size)
>>>>    {
>>>
>>> I notice that this, and the uniphier implementations are the only
>>> non-inline ones. Is the problem we later conflict with your changes,
>>> perhaps because this wasn't marked inline? Thanks.
>>>
>>
>> https://lore.kernel.org/u-boot/d63d53bd-3f63-430d-b0bc-2379b7bded81@rock-chips.com/
>>
>> so essentially
>>
>> lib/efi/efi_stub.c:86:13: error: '_debug_uart_putc' defined but not
>> used [-Werror=unused-function]
>>     86 | static void _debug_uart_putc(int ch)
>>
>> I tested by adding inline and indeed it fixes the warning.
>>
>> Somehow the non-inlined _debug_uart_init doesn't seem to be triggering any
>> warning though.
>>
>> Would you recommend to inline the _debug_uart_putc function instead of
>> guarding the whole thing with ifdefery?
> 
> Yes please, and also fixing up uniphier for consistency (it won't have
> the warning because it doesn't descend to that directory unless the
> option is enabled).
> 

I actually added an #error in the function and it is compiled and 
doesn't show a warning, so not sure what I'm missing?

Quentin