Re: [PATCH v3 1/3] Kconfig : Remove HAS_IOMEM dependency for Graphics support

From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Thomas Huth <thuth@redhat.com>, Cornelia Huck <cohuck@redhat.com>
Cc: Farhan Ali <alifm@linux.vnet.ibm.com>,
	linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
	linux-fbdev@vger.kernel.org, geert@linux-m68k.org,
	tomi.valkeinen@ti.com, b.zolnierkie@samsung.com
Subject: Re: [PATCH v3 1/3] Kconfig : Remove HAS_IOMEM dependency for Graphics support
Date: Wed, 21 Feb 2018 12:22:04 +0100	[thread overview]
Message-ID: <1f8907d4-c4a3-d41b-8834-679dcc85de4a@de.ibm.com> (raw)
In-Reply-To: <d1a89481-e5c9-b460-ea9c-f796dc28b748@redhat.com>

On 02/21/2018 12:14 PM, Thomas Huth wrote:
> On 21.02.2018 12:09, Christian Borntraeger wrote:
>>
>>
>> On 02/21/2018 11:32 AM, Cornelia Huck wrote:
>>> On Wed, 21 Feb 2018 11:22:38 +0100
>>> Christian Borntraeger <borntraeger@de.ibm.com> wrote:
>>>
>>>> On 02/21/2018 11:05 AM, Christian Borntraeger wrote:
>>>>>
>>>>>
>>>>> On 02/19/2018 05:38 PM, Farhan Ali wrote:  
>>>>>>
>>>>>>
>>>>>> On 02/19/2018 11:25 AM, Thomas Huth wrote:  
>>>>>>> On 19.02.2018 16:47, Farhan Ali wrote:  
>>>>>>>> The 'commit e25df1205f37 ("[S390] Kconfig: menus with depends on HAS_IOMEM.")'
>>>>>>>> added the HAS_IOMEM dependecy for "Graphics support". This disabled the
>>>>>>>> "Graphics support" menu for S390. But if we enable VT layer for S390,
>>>>>>>> we would also need to enable the dummy console. So let's remove the
>>>>>>>> HAS_IOMEM dependency.
>>>>>>>>
>>>>>>>> Move this dependency to sub menu items and console drivers that use
>>>>>>>> io memory.
>>>>>>>>
>>>>>>>> Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
>>>>>>>> ---
>>>>>>>>   drivers/video/Kconfig         | 21 +++++++++++----------
>>>>>>>>   drivers/video/console/Kconfig |  4 ++--
>>>>>>>>   2 files changed, 13 insertions(+), 12 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
>>>>>>>> index 3c20af9..8f10915 100644
>>>>>>>> --- a/drivers/video/Kconfig
>>>>>>>> +++ b/drivers/video/Kconfig
>>>>>>>> @@ -3,7 +3,6 @@
>>>>>>>>   #
>>>>>>>>     menu "Graphics support"
>>>>>>>> -    depends on HAS_IOMEM
>>>>>>>>     config HAVE_FB_ATMEL
>>>>>>>>       bool
>>>>>>>> @@ -11,20 +10,22 @@ config HAVE_FB_ATMEL
>>>>>>>>   config SH_LCD_MIPI_DSI
>>>>>>>>       bool
>>>>>>>>   -source "drivers/char/agp/Kconfig"
>>>>>>>> +if HAS_IOMEM
>>>>>>>> +    source "drivers/char/agp/Kconfig"
>>>>>>>>   -source "drivers/gpu/vga/Kconfig"
>>>>>>>> +    source "drivers/gpu/vga/Kconfig"
>>>>>>>>   -source "drivers/gpu/host1x/Kconfig"
>>>>>>>> -source "drivers/gpu/ipu-v3/Kconfig"
>>>>>>>> +    source "drivers/gpu/host1x/Kconfig"
>>>>>>>> +    source "drivers/gpu/ipu-v3/Kconfig"
>>>>>>>>   -source "drivers/gpu/drm/Kconfig"
>>>>>>>> +    source "drivers/gpu/drm/Kconfig"  
>>>>>
>>>>>
>>>>> Hmmm, looks like that this makes it impossible to select VIRTIO_GPU - need still more
>>>>> work.
>>>>>   
>>>> Sorry my fault. I had CONFIG_PCI disabled.
>>>
>>> That smells like the s390 HAS_IOMEM stuff needs more work -- I guess
>>> that you want to enable a ccw virtio-gpu device, not a pci one, right?
>>
>> It is a ccw virtio-gpu. But s390 has no IOMEM without CONFIG_PCI, so you cannot
>> select VIRTIO_GPU, which needs DRM, which need IOMEM.
> 
> So the 'source "drivers/gpu/drm/Kconfig"' should maybe rather reside
> outside of the "if HAS_IOMEM" path? Or does it not compile anymore that way?

virtio-gpu depends on drm. So in essence it boils down to if you want virtio-gpu
you also need to enable PCI, even if the actual channel is ccw.