Hi Arnd, On Mon, Jan 08, 2018 at 01:52:28PM +0100, Arnd Bergmann wrote: > Without CONFIG_MEDIA_CONTROLLER, the new driver fails to build: > > drivers/perf/arm_dsu_pmu.c: In function 'dsu_pmu_probe_pmu': > drivers/perf/arm_dsu_pmu.c:661:2: error: implicit declaration of function 'bitmap_from_u32array'; did you mean 'bitmap_from_arr32'? [-Werror=implicit-function-declaration] There seems to be a build error with this driver if Media controller is disabled, but this is not the error message nor adding a dependency to Media controller is a sound fix for it. drivers/media/i2c/ov7740.c: In function ‘ov7740_probe’: drivers/media/i2c/ov7740.c:1139:38: error: ‘struct v4l2_subdev’ has no member named ‘entity’ media_entity_cleanup(&ov7740->subdev.entity); I think it'd be worth adding nop variants for functions that are commonly used by drivers that can be built with or without the Media controller. I'll send a patch. > > This adds a dependency similar to what we have for other drivers > like this. > > Fixes: 39c5c4471b8d ("media: i2c: Add the ov7740 image sensor driver") > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > drivers/media/i2c/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig > index 9f18cd296841..03cf3a1a1e06 100644 > --- a/drivers/media/i2c/Kconfig > +++ b/drivers/media/i2c/Kconfig > @@ -667,7 +667,7 @@ config VIDEO_OV7670 > > config VIDEO_OV7740 > tristate "OmniVision OV7740 sensor support" > - depends on I2C && VIDEO_V4L2 > + depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER > depends on MEDIA_CAMERA_SUPPORT > ---help--- > This is a Video4Linux2 sensor-level driver for the OmniVision -- Kind regards, Sakari Ailus sakari.ailus@xxxxxxxxxxxxxxx