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Date:   Wed, 27 Oct 2021 15:12:32 -0700 (PDT)
Subject:     Re: [PATCH 1/1] riscv: defconfig: enable DRM_NOUVEAU
In-Reply-To: <a4f8fad0-4ae4-5a7e-1691-ae46abd061fa@canonical.com>
CC:     Damien Le Moal <Damien.LeMoal@wdc.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        aou@eecs.berkeley.edu, Anup Patel <Anup.Patel@wdc.com>,
        axboe@kernel.dk, sagar.kadam@sifive.com,
        Atish Patra <Atish.Patra@wdc.com>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     heinrich.schuchardt@canonical.com
Message-ID: <mhng-ecb4debb-aa09-4102-bbf4-0223eff391d7@palmerdabbelt-glaptop>
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On Wed, 27 Oct 2021 00:31:54 PDT (-0700), heinrich.schuchardt@canonical.com wrote:
> On 10/27/21 04:31, Damien Le Moal wrote:
>> On 2021/10/27 8:58, Palmer Dabbelt wrote:
>>> On Tue, 12 Oct 2021 09:46:58 PDT (-0700), heinrich.schuchardt@canonical.com wrote:
>>>> Both RADEON and NOUVEAU graphics cards are supported on RISC-V. Enabling
>>>> the one and not the other does not make sense.
>>>>
>>>> As typically at most one of RADEON, NOUVEAU, or VIRTIO GPU support will be
>>>> needed DRM drivers should be compiled as modules.
>>>
>>> Do you have an nVidia card that works on real hardware?  Last I checked
>>> was a while ago, but they weren't working at the time (IIRC it was
>>> something to do with PCIe addressing, but it was a hardware limitation
>>> so I don't remember exactly how it all fits together).
>>>
>>> If they work then I'm happy to flip them on.
>
> My SiFive Unmatched is running KDE on a GT710.
>
> It would be unfair to treat the two major GPU vendors AMD and Nvidia
> differently.
>
>>
>> Why enable this at all ? If they do not work, then disabling theses cards make
>> sense. But if they do work, isn't leaving the config to be the default defined
>> by the driver the preferred approach ? Otherwise, we will eventually end-up with
>> a defconfig that has everything enabled...
>
> If you want to get your system up, having keyboard input and GPU output
> is the bare minimum that you need to proceed unless you are a developer
> working over UART and have a second system available.
>
> To keep the kernel small DRM drivers should be modules.

I can buy the argument for not having any of this in arch defconfigs, 
but in practice there's a lot of stuff in defconfigs that I don't really 
think should be arch decisions (ext4, for example).  If we've got AMD in 
there and the nVidia cards work then I don't see any reason to 
differentiate between the two, so let's just do the same thing for both.

This is on for-next.

>
> Best regards
>
> Heinrich
>
>>
>>>
>>>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
>>>> ---
>>>>   arch/riscv/configs/defconfig | 7 ++++---
>>>>   1 file changed, 4 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig
>>>> index 4ebc80315f01..c252fd5706d2 100644
>>>> --- a/arch/riscv/configs/defconfig
>>>> +++ b/arch/riscv/configs/defconfig
>>>> @@ -72,9 +72,10 @@ CONFIG_GPIOLIB=y
>>>>   CONFIG_GPIO_SIFIVE=y
>>>>   # CONFIG_PTP_1588_CLOCK is not set
>>>>   CONFIG_POWER_RESET=y
>>>> -CONFIG_DRM=y
>>>> -CONFIG_DRM_RADEON=y
>>>> -CONFIG_DRM_VIRTIO_GPU=y
>>>> +CONFIG_DRM=m
>>>> +CONFIG_DRM_RADEON=m
>>>> +CONFIG_DRM_NOUVEAU=m
>>>> +CONFIG_DRM_VIRTIO_GPU=m
>>>>   CONFIG_FRAMEBUFFER_CONSOLE=y
>>>>   CONFIG_USB=y
>>>>   CONFIG_USB_XHCI_HCD=y
>>>
>>> _______________________________________________
>>> linux-riscv mailing list
>>> linux-riscv@lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>>>
>>
>>