From: Arnd Bergmann <arnd@xxxxxxxx> At the moment, accel drivers can be built-in even with CONFIG_DRM=m, but this causes a link failure: x86_64-linux-ld: drivers/accel/ivpu/ivpu_drv.o: in function `ivpu_dev_init': ivpu_drv.c:(.text+0x1535): undefined reference to `drmm_kmalloc' x86_64-linux-ld: ivpu_drv.c:(.text+0x1562): undefined reference to `drmm_kmalloc' x86_64-linux-ld: drivers/accel/ivpu/ivpu_drv.o: in function `ivpu_remove': ivpu_drv.c:(.text+0x1faa): undefined reference to `drm_dev_unregister' x86_64-linux-ld: drivers/accel/ivpu/ivpu_drv.o: in function `ivpu_probe': ivpu_drv.c:(.text+0x1fef): undefined reference to `__devm_drm_dev_alloc' This could be avoided by making DRM_ACCEL a tristate symbol, which would mean that every ACCEL driver is guarantee to be able to link against DRM as well. However, having both as =m causes another link failure because the DRM core code also links against the accel driver: x86_64-linux-ld: drivers/gpu/drm/drm_drv.o: in function `drm_minor_register': drm_drv.c:(.text+0x259): undefined reference to `accel_debugfs_init' x86_64-linux-ld: drm_drv.c:(.text+0x298): undefined reference to `accel_minor_replace' I think it will be necessary to establish a link hierarchy between drm.ko and drm_accel.ko to avoid circular dependencies like this, but until then the only way that both can be used is to have both subsystems built into the kernel. Enforce this using a Kconfig dependency. Fixes: 8bf4889762a8 ("drivers/accel: define kconfig and register a new major") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/accel/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig index 834863902e16..dd18d3b2028c 100644 --- a/drivers/accel/Kconfig +++ b/drivers/accel/Kconfig @@ -8,7 +8,7 @@ # menuconfig DRM_ACCEL bool "Compute Acceleration Framework" - depends on DRM + depends on DRM=y help Framework for device drivers of compute acceleration devices, such as, but not limited to, Machine-Learning and Deep-Learning -- 2.39.0