[U-Boot] [PATCH 04/26] x86: irq: Reserve IRQ9 for ACPI in PIC mode

[Stefan Roese]

Hi Bin,

On 03.05.2016 14:46, Bin Meng wrote:
> On Tue, May 3, 2016 at 8:29 PM, Stefan Roese <sr at denx.de> wrote:
>> Hi Bin,
>>
>> On 02.05.2016 09:33, Bin Meng wrote:
>>>
>>> Reserve IRQ9 which is to be used as SCI interrupt number
>>> for ACPI in PIC mode.
>>>
>>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>>> ---
>>>
>>>    arch/x86/cpu/irq.c | 4 ++++
>>>    1 file changed, 4 insertions(+)
>>>
>>> diff --git a/arch/x86/cpu/irq.c b/arch/x86/cpu/irq.c
>>> index 2950783..ae90b0c 100644
>>> --- a/arch/x86/cpu/irq.c
>>> +++ b/arch/x86/cpu/irq.c
>>> @@ -120,6 +120,10 @@ static int create_pirq_routing_table(struct udevice
>>> *dev)
>>>
>>>          priv->irq_mask = fdtdec_get_int(blob, node,
>>>                                          "intel,pirq-mask", PIRQ_BITMAP);
>>> +#ifdef CONFIG_GENERATE_ACPI_TABLE
>>> +       /* Reserve IRQ9 for SCI */
>>> +       priv->irq_mask &= ~(1 << 9);
>>> +#endif
>>
>>
>> Does it make sense to change this into using IS_ENABLED()?
>>
>>          if (IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE)) {
>>                  /* Reserve IRQ9 for SCI */
>>                  priv->irq_mask &= ~(1 << 9);
>>          }
>>
>> To drop the #ifdef here?
>>
>
> Ah, this bothers me sometimes. I see some places in U-Boot uses #ifdef
> but IS_ENABLED somewhere else.  I am not sure what the recommended
> guideline of U-Boot with regard to this?

We definitely strive to remove (or at least not add new) #ifdef's
from the U-Boot code base. And IS_ENABLED() is a good way to
achieve this. But it can only be used with config options available
via Kconfig. And since CONFIG_GENERATE_ACPI_TABLE is a Kconfig
symbol, my recommendation is to use it.

Thanks,
Stefan