Re: [PATCH] s390/console: enable dummy console for vt

From: Christian Borntraeger
Date: Thu Feb 15 2018 - 07:02:30 EST




On 02/15/2018 12:57 PM, Thomas Huth wrote:
> On 15.02.2018 12:26, Geert Uytterhoeven wrote:
>> Hi Christian,
>>
>> On Thu, Feb 15, 2018 at 12:14 PM, Christian Borntraeger
>> <borntraeger@xxxxxxxxxx> wrote:
>>> To enable the virtual terminal layer with virtio-gpu, we need to
>>> provide the dummy console. This console is hidden behind CONFIG_IOMEM
>>> via the graphics support. Instead of fully enabling the graphic
>>> drivers lets just provide a Kconfig option for the dummy console.
>>>
>>> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
>>> ---
>>> New version: instead of moving around the graphic and console stuff,
>>> let's just keep an s390 specific variant of CONFIG_DUMMY_CONSOLE
>>> arch/s390/Kconfig | 5 +++++
>>> 1 file changed, 5 insertions(+)
>>>
>>> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
>>> index cbe1d978693a..a69690f616f3 100644
>>> --- a/arch/s390/Kconfig
>>> +++ b/arch/s390/Kconfig
>>> @@ -952,6 +952,11 @@ config S390_HYPFS_FS
>>>
>>> source "arch/s390/kvm/Kconfig"
>>>
>>> +config DUMMY_CONSOLE
>>> + bool
>>> + depends on VT
>>> + default y
>>> +
>>> config S390_GUEST
>>> def_bool y
>>> prompt "s390 support for virtio devices"
>>
>> Really?
>>
>> You already have your own copy of HAS_IOMEM, which makes it hard for
>> people to track which one applies where.
>
> I think I agree with Geert - let's better fix this in a proper way
> instead of doing hacks like this. I guess there will be other
> architectures in the future that might want to use the dummy console
> without CONFIG_IOMEM, so fixing this in drivers/video/ instead sounds
> better to me.

The question is, what is the proper fix?