Re: [PATCH 1/2] media: v4l: cadence: add VIDEO_V4L2 dependency

[Maxime Ripard]

On Thu, May 31, 2018 at 12:07:10AM +0200, Arnd Bergmann wrote:
> The cadence media drivers can be built-in while the v4l2 core is a loadable
> module. This is a mistake and leads to link errors:
> 
> drivers/media/v4l2-core/v4l2-fwnode.o: In function `v4l2_async_register_subdev_sensor_common':
> v4l2-fwnode.c:(.text+0x12f0): undefined reference to `v4l2_async_subdev_notifier_register'
> v4l2-fwnode.c:(.text+0x1304): undefined reference to `v4l2_async_register_subdev'
> v4l2-fwnode.c:(.text+0x1318): undefined reference to `v4l2_async_notifier_unregister'
> v4l2-fwnode.c:(.text+0x1338): undefined reference to `v4l2_async_notifier_cleanup'
> cdns-csi2rx.c:(.text+0x9f8): undefined reference to `v4l2_subdev_init'
> cdns-csi2rx.c:(.text+0xa78): undefined reference to `v4l2_async_register_subdev'
> drivers/media/platform/cadence/cdns-csi2tx.o: In function `csi2tx_remove':
> cdns-csi2tx.c:(.text+0x88): undefined reference to `v4l2_async_unregister_subdev'
> drivers/media/platform/cadence/cdns-csi2tx.o: In function `csi2tx_probe':
> cdns-csi2tx.c:(.text+0x884): undefined reference to `v4l2_subdev_init'
> cdns-csi2tx.c:(.text+0xa9c): undefined reference to `v4l2_async_register_subdev'
> 
> An explicit Kconfig dependency on VIDEO_V4L2 avoids the problem.
> 
> Fixes: 1fc3b37f34f6 ("media: v4l: cadence: Add Cadence MIPI-CSI2 RX driver")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Acked-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>

Thanks!
Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com