s390/console: enable dummy console for vt

Submitted by Christian Borntraeger on Feb. 15, 2018, 11:14 a.m.

Details

Message ID 20180215111423.96598-1-borntraeger@de.ibm.com
State New
Headers show
Series "Series without cover letter" ( rev: 3 ) in DRI devel

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Commit Message

Christian Borntraeger Feb. 15, 2018, 11:14 a.m.
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@de.ibm.com>
---
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(+)

Patch hide | download patch | download mbox

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"

Comments

Hi Christian,

On Thu, Feb 15, 2018 at 12:14 PM, Christian Borntraeger
<borntraeger@de.ibm.com> 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@de.ibm.com>
> ---
> 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.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
On 15.02.2018 12:26, Geert Uytterhoeven wrote:
> Hi Christian,
> 
> On Thu, Feb 15, 2018 at 12:14 PM, Christian Borntraeger
> <borntraeger@de.ibm.com> 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@de.ibm.com>
>> ---
>> 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.

 Thomas
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@de.ibm.com> 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@de.ibm.com>
>>> ---
>>> 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?
On 02/15/2018 07:02 AM, Christian Borntraeger wrote:
> 
> 
> 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@de.ibm.com> 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@de.ibm.com>
>>>> ---
>>>> 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?
> 

How about we only fence off sub menu items such as DRM or GPU or Fbdev, 
which actually uses io memory, in drivers/video/Kconfig? Similar to what 
Thomas suggested for moving the CONFIG_IOMEM dependency for fbdevs?
On 02/19/2018 02:35 PM, Farhan Ali wrote:
> 
> 
> On 02/15/2018 07:02 AM, Christian Borntraeger wrote:
>>
>>
>> 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@de.ibm.com> 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@de.ibm.com>
>>>>> ---
>>>>> 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?
>>
> 
> How about we only fence off sub menu items such as DRM or GPU or Fbdev, which actually uses io memory, in drivers/video/Kconfig? Similar to what Thomas suggested for moving the CONFIG_IOMEM dependency for fbdevs?

Can you spin a patch?
On 02/19/2018 08:37 AM, Christian Borntraeger wrote:
> 
> 
> On 02/19/2018 02:35 PM, Farhan Ali wrote:
>>
>>
>> On 02/15/2018 07:02 AM, Christian Borntraeger wrote:
>>>
>>>
>>> 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@de.ibm.com> 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@de.ibm.com>
>>>>>> ---
>>>>>> 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?
>>>
>>
>> How about we only fence off sub menu items such as DRM or GPU or Fbdev, which actually uses io memory, in drivers/video/Kconfig? Similar to what Thomas suggested for moving the CONFIG_IOMEM dependency for fbdevs?
> 
> Can you spin a patch?
> 
Yes, I will post it as V3.