On Sat, Jul 24, 2021 at 2:52 PM Karol Herbst kherbst@redhat.com wrote:
On Sat, Jul 24, 2021 at 2:10 PM Karol Herbst kherbst@redhat.com wrote:
On Sat, Jul 24, 2021 at 1:56 PM Arnd Bergmann arnd@kernel.org wrote:
On Sat, Jul 24, 2021 at 11:55 AM Karol Herbst kherbst@redhat.com wrote:
- You run into dependency loops that prevent a successful build when some other driver has a 'depends on'. Preventing these loops was the main reason I said we should do this change.
In theory we could change the other 85 drivers that use 'depends on' today, and make BACKLIGHT_CLASS_DEVICE a hidden symbol that only ever selected by the drivers that need it. This would avoid the third problem but not the other one.
I see. Yeah, I guess we can do it this way then. I just wasn't aware of the bigger picture here. Thanks for explaining.
yeah... that doesn't work. So the issue is, that X86_PLATFORM_DEVICES is a little bit in the way. If I remove the select X86_PLATFORM_DEVICES then I guess problems once ACPI is enabled, but if I keep it, I get cyclic dep errors :/
Right, this is the exact problem I explained: since all other drivers use 'depends on X86_PLATFORM_DEVICES' instead of 'select', you get a loop again. Prior to changing the BACKLIGHT_CLASS_DEVICE dependency, nouveau was pretty much on top of everything else in the hierarchy, changing part of it can result in a loop.
I see that there are about ten more 'select' statements that look like they should not be there, and almost all of them were added in order to be able to 'select MXM_WMI'.
I think we can go as far as the patch below, which I've put in my randconfig build machine, on top of your patch. I'm not entirely sure how strong the dependency on MXM_WMI is: does it cause a build failure when that is not enabled, or was this select just added for convenience so users don't get surprised when it's missing?
Arnd
diff --git a/drivers/gpu/drm/nouveau/Kconfig b/drivers/gpu/drm/nouveau/Kconfig index 9c2108b48524..f2585416507e 100644 --- a/drivers/gpu/drm/nouveau/Kconfig +++ b/drivers/gpu/drm/nouveau/Kconfig @@ -3,21 +3,14 @@ config DRM_NOUVEAU tristate "Nouveau (NVIDIA) cards" depends on DRM && PCI && MMU depends on AGP || !AGP + depends on ACPI_VIDEO || !ACPI + depends on BACKLIGHT_CLASS_DEVICE + depends on MXM_WMI || !X86 || !ACPI select IOMMU_API select FW_LOADER select DRM_KMS_HELPER select DRM_TTM select DRM_TTM_HELPER - select BACKLIGHT_CLASS_DEVICE - select ACPI_VIDEO if ACPI && X86 && INPUT - select X86_PLATFORM_DEVICES if ACPI && X86 - select ACPI_WMI if ACPI && X86 - select MXM_WMI if ACPI && X86 - select POWER_SUPPLY - # Similar to i915, we need to select ACPI_VIDEO and it's dependencies - select INPUT if ACPI && X86 - select THERMAL if ACPI && X86 - select ACPI_VIDEO if ACPI && X86 select SND_HDA_COMPONENT if SND_HDA_CORE help Choose this option for open-source NVIDIA support.