2019-07-08 15:23:57

by Arnd Bergmann

Subject: [PATCH] drm/exynos: add CONFIG_MMU dependency

Compile-testing this driver on a NOMMU configuration shows a link failure:

drivers/gpu/drm/exynos/exynos_drm_gem.o: In function `exynos_drm_gem_fault':
exynos_drm_gem.c:(.text+0x484): undefined reference to `vmf_insert_mixed'

Add a CONFIG_MMU dependency to ensure we only enable this in configurations
that build correctly.

Many other drm drivers have the same dependency. It would be nice to
make this work in MMU-less configurations, but evidently nobody has
ever needed this so far.

Fixes: 156bdac99061 ("drm/exynos: trigger build of all modules")
Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/gpu/drm/exynos/Kconfig | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
index 60ce4a8ad9e1..6f7d3b3b3628 100644
--- a/drivers/gpu/drm/exynos/Kconfig
+++ b/drivers/gpu/drm/exynos/Kconfig
@@ -2,6 +2,7 @@
config DRM_EXYNOS
tristate "DRM Support for Samsung SoC EXYNOS Series"
depends on OF && DRM && (ARCH_S3C64XX || ARCH_S5PV210 || ARCH_EXYNOS || ARCH_MULTIPLATFORM || COMPILE_TEST)
+ depends on MMU
select DRM_KMS_HELPER
select VIDEOMODE_HELPERS
select SND_SOC_HDMI_CODEC if SND_SOC
--
2.20.0

2019-07-08 19:14:26

by Vladimir Murzin

Subject: Re: [PATCH] drm/exynos: add CONFIG_MMU dependency

On 7/8/19 2:46 PM, Arnd Bergmann wrote:
> Compile-testing this driver on a NOMMU configuration shows a link failure:
>
> drivers/gpu/drm/exynos/exynos_drm_gem.o: In function `exynos_drm_gem_fault':
> exynos_drm_gem.c:(.text+0x484): undefined reference to `vmf_insert_mixed'
>
> Add a CONFIG_MMU dependency to ensure we only enable this in configurations
> that build correctly.
>
> Many other drm drivers have the same dependency. It would be nice to
> make this work in MMU-less configurations, but evidently nobody has
> ever needed this so far.
>
> Fixes: 156bdac99061 ("drm/exynos: trigger build of all modules")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> drivers/gpu/drm/exynos/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
> index 60ce4a8ad9e1..6f7d3b3b3628 100644
> --- a/drivers/gpu/drm/exynos/Kconfig
> +++ b/drivers/gpu/drm/exynos/Kconfig
> @@ -2,6 +2,7 @@
> config DRM_EXYNOS
> tristate "DRM Support for Samsung SoC EXYNOS Series"
> depends on OF && DRM && (ARCH_S3C64XX || ARCH_S5PV210 || ARCH_EXYNOS || ARCH_MULTIPLATFORM || COMPILE_TEST)
> + depends on MMU
> select DRM_KMS_HELPER
> select VIDEOMODE_HELPERS
> select SND_SOC_HDMI_CODEC if SND_SOC
>

I seen

ERROR: "vmf_insert_mixed" [drivers/gpu/drm/exynos/exynosdrm.ko] undefined!

with older kernels when driver was build as a module, so FWIW

Reviewed-by: Vladimir Murzin <[email protected]>

Cheers
Vladimir