[PATCH 6/8] drm: decouple from CONFIG_FB

[Arnd Bergmann]

On Fri, Apr 17, 2020 at 6:50 PM Sam Ravnborg <sam at ravnborg.org> wrote:

>
> So what this try to say is that we cannot have FB a module while DRM is
> built-in (marked N in the above).

Correct

>
> Could you explain in the changelog why this combination is not good.
> (Or tell me if my analysis was flawed).

I agree in hindsight this was less obvious than I thought ;-)

Added this text to the changelog:

|  When CONFIG_FB is a loadable module, DRM_KMS_FB_HELPER cannot be
| part of the built-in subsystem, so add dependency to ensure this
| can only be enabled if the DRM module can successfully be linked.

and this comment in the Kconfig file:

@@ -112,7 +112,7 @@ config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
 config DRM_FBDEV_EMULATION
        bool "Enable legacy fbdev support for your modesetting driver"
        depends on DRM && FB
-       depends on FB=y || DRM=m
+       depends on FB=y || DRM=m # DRM_KMS_FB_HELPER links against FB
        select DRM_KMS_HELPER
        select DRM_KMS_FB_HELPER
        default y

Let me know if you think those changes are sufficient

> With this fixed (assuming I am right):
> Reviewed-by: Sam Ravnborg <sam at ravnborg.org>

Thanks!

        Arnd