From 347f7a3763601d7b466898d1f10080b7083ac4a3 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Sat, 21 Dec 2013 05:42:11 -0200 Subject: [PATCH] [media] subdev autoselect only works if I2C and I2C_MUX is selected As reported by the kbuild test robot : > warning: (VIDEO_EM28XX_DVB) selects DVB_M88DS3103 which has unmet direct dependencies (MEDIA_SUPPORT && DVB_CORE && I2C && I2C_MUX) > drivers/built-in.o: In function `m88ds3103_release': > >> m88ds3103.c:(.text+0x1ab1af): undefined reference to `i2c_del_mux_adapter' > drivers/built-in.o: In function `m88ds3103_attach': > >> (.text+0x1ab342): undefined reference to `i2c_add_mux_adapter' There are 3 possible ways to fix it: 1) make em28xx dependent on I2C_MUX. That sounds wrong, as the em28xx bridge doesn't have i2c muxes on it, and just one frontend has. Well, subdevs could eventually be converted to, instead of using dvb i2c gate control, to use i2c mux support. That makes sense, but it takes time and lots of effort. Not sure if this will happen anytime soon. 2) MEDIA_SUBDRV_AUTOSELECT can be dependent of I2C and I2C_MUX. That means that users will need to manually enable I2C_MUX on some distributions. Not sure about others, but, on Fedora, this option is disabled. So, it can end by generating a number of complains from users that their devices suddenly stopped working after a Kernel upgrade, at least until all distros that ship Kernels with I2C_MUX enabled. 3) if MEDIA_SUBDRV_AUTOSELECT is selected, it will select I2C and I2C_MUX. Of course, MEDIA_SUBDRV_AUTOSELECT will need to inherit all dependencies that I2C and I2C_MUX have (only HAS_IOMEM). The disadvantage is that, if new dependencies are added on I2C, they'll also need to be added here. As the hole idea of autoselect is to let the user not bother about whatever frontend/tuner is used by a driver, IMHO, (3) is the better solution. Reported-by: kbuild test robot Signed-off-by: Mauro Carvalho Chehab --- drivers/media/Kconfig | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig index 8270388e2a0d..1d0758aeb8e4 100644 --- a/drivers/media/Kconfig +++ b/drivers/media/Kconfig @@ -172,6 +172,9 @@ comment "Media ancillary drivers (tuners, sensors, i2c, frontends)" config MEDIA_SUBDRV_AUTOSELECT bool "Autoselect ancillary drivers (tuners, sensors, i2c, frontends)" depends on MEDIA_ANALOG_TV_SUPPORT || MEDIA_DIGITAL_TV_SUPPORT || MEDIA_CAMERA_SUPPORT + depends on HAS_IOMEM + select I2C + select I2C_MUX default y help By default, a media driver auto-selects all possible ancillary -- 2.39.5