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

From: Farhan Ali
Date: Mon Feb 19 2018 - 08:36:10 EST




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@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?


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?