Re: [Qemu-devel] [Qemu-arm] [PATCH 2/4] hw/core: Add a config switch for the "or-irq" device

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 5/14/19 12:06 PM, Peter Maydell wrote:
> On Tue, 14 May 2019 at 11:00, Thomas Huth <thuth@redhat.com> wrote:
>>
>> The "or-irq" device is only used by certain machines. Let's add
>> a proper config switch for it so that it only gets compiled when we
>> really need it.
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>> ---
>>  hw/arm/Kconfig        | 2 ++
>>  hw/core/Kconfig       | 3 +++
>>  hw/core/Makefile.objs | 2 +-
>>  hw/pci-host/Kconfig   | 3 ++-
>>  4 files changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
>> index af8cffde9c..0bb3bbe9d3 100644
>> --- a/hw/arm/Kconfig
>> +++ b/hw/arm/Kconfig
>> @@ -277,6 +277,7 @@ config RASPI
>>  config STM32F205_SOC
>>      bool
>>      select ARM_V7M
>> +    select OR_IRQ
>>      select STM32F2XX_TIMER
>>      select STM32F2XX_USART
>>      select STM32F2XX_SYSCFG
>> @@ -424,6 +425,7 @@ config ARMSSE
>>      select IOTKIT_SECCTL
>>      select IOTKIT_SYSCTL
>>      select IOTKIT_SYSINFO
>> +    select OR_IRQ
>>      select TZ_MPC
>>      select TZ_MSC
>>      select TZ_PPC
> 
> In cases like this where a device is used both by
> an SoC and also directly by the board code that uses
> that SoC, should we put the select OR_IRQ only in
> the SoC's config, or also in the board model's config
> (ie, in "config MPS2" as well as "config ARMSSE") ?

Someone should be able to work on the board without having to look at
the SoC code/config, so both :) The idea of Kconfig is you only worry
about a specific device, and the qgraph sort the rest out.

So having in both place is safer, and helps to visualize dependencies in
the graph tree (I'm slowly working on this feature to help new-comer to
understand model dependencies).