Re: [PATCH V2 13/14] LoongArch: Adjust default config files for 32BIT/64BIT

[Huacai Chen]

Hi, Arnd,

On Tue, Nov 18, 2025 at 9:46 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Tue, Nov 18, 2025, at 12:27, Huacai Chen wrote:
> > Add loongson32_defconfig (for 32BIT) and rename loongson3_defconfig to
> > loongson64_defconfig (for 64BIT).
> >
> > Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > ---
> >  arch/loongarch/configs/loongson32_defconfig   | 1110 +++++++++++++++++
> >  ...ongson3_defconfig => loongson64_defconfig} |    0
>
> I would suggest using .config fragment here and only listing
> the differences in the defconfig files in there, rather than
> duplicating everything.
>
> > +CONFIG_DMI=y
> > +CONFIG_EFI=y
> > +CONFIG_SUSPEND=y
> > +CONFIG_HIBERNATION=y
> > +CONFIG_ACPI=y
> > +CONFIG_ACPI_SPCR_TABLE=y
> > +CONFIG_ACPI_TAD=y
> > +CONFIG_ACPI_DOCK=y
> > +CONFIG_ACPI_IPMI=m
> > +CONFIG_ACPI_HOTPLUG_CPU=y
> > +CONFIG_ACPI_PCI_SLOT=y
> > +CONFIG_ACPI_HOTPLUG_MEMORY=y
> > +CONFIG_ACPI_BGRT=y
>
> You mention that loongarch32 uses ftb based boot,
> so ACPI should probably be disabled here.
I have tried my best, adding #ifdef CONFIG_ACPI all over the world but
still failed. :)

LoongArch is deeply coupled with ACPI and can hardly disabled. On the
other hand, it is not forbidden to use ACPI for LoongArch32. So let's
keep it, and I will modify the description for LoongArch32 booting.

>
> > +CONFIG_DRM=y
> > +CONFIG_DRM_LOAD_EDID_FIRMWARE=y
> > +CONFIG_DRM_RADEON=m
> > +CONFIG_DRM_RADEON_USERPTR=y
> > +CONFIG_DRM_AMDGPU=m
> > +CONFIG_DRM_AMDGPU_SI=y
> > +CONFIG_DRM_AMDGPU_CIK=y
> > +CONFIG_DRM_AMDGPU_USERPTR=y
> > +CONFIG_DRM_AST=y
> > +CONFIG_DRM_QXL=m
> > +CONFIG_DRM_VIRTIO_GPU=m
> > +CONFIG_DRM_LOONGSON=y
> > +CONFIG_DRM_SIMPLEDRM=y
> > +CONFIG_FB=y
> > +CONFIG_FB_EFI=y
> > +CONFIG_FB_RADEON=y
> > +CONFIG_FIRMWARE_EDID=y
>
> Is AMDGPU actually working? This driver is rather tricky to get
> reliable on new architectures.
Never tried and probably not work. I will remove it.

>
> I would suggest turning off CONFIG_FB here (also on loongarch64).
> There is a replacement driver for FB_EFI in DRM now.
Do you mean simpledrm? It probably works but not always works. From
sysfb_init() we know it only mark EFIFB as a simpledrm device when
"compatible", so we still need FB_EFI as a fallback.

Huacai

>
>        Arnd
>