On Wednesday 17 March 2010 20:28:07 Mauro Carvalho Chehab wrote: > Guennadi Liakhovetski wrote: > > > Hi Mauro > > > > we just discussed this with Hans on IRC, and if I understood him > > correctly, he was of the same opinion, that adding such a variable could > > help. > > > > The problem is the following: this automatic selection works in a way, > > that various bridge drivers select "helper" chip drivers (i2c subdevice > > drivers" if this autoselection is enabled, e.g. > > > > config VIDEO_MXB > > tristate "Siemens-Nixdorf 'Multimedia eXtension Board'" > > depends on PCI && VIDEO_V4L1 && I2C > > select VIDEO_SAA7146_VV > > select VIDEO_TUNER > > select VIDEO_SAA711X if VIDEO_HELPER_CHIPS_AUTO > > select VIDEO_TDA9840 if VIDEO_HELPER_CHIPS_AUTO > > select VIDEO_TEA6415C if VIDEO_HELPER_CHIPS_AUTO > > select VIDEO_TEA6420 if VIDEO_HELPER_CHIPS_AUTO > > > > With SoC-based set ups this cannot work. The only location where this > > information is available is platform code under arch/... and selecting > > these drivers from there would be awkward imho. > > Kconfig works fine if the var is on another place. So, you could do things > like: > > config VIDEO_xxx > select VIDEO_foo if VIDEO_HELPER_CHIPS_AUTO && ARCH_bar > > You may even convert it into dependencies like: > > config VIDEO_I2C_foo > depends on ARCH_bar && config VIDEO_xxx > default y if VIDEO_HELPER_CHIPS_AUTO I2C drivers are NOT dependent on architectures. They can be used anywhere. > > The depends on syntax generally works better than using select. We've converted > some select into depends on a few places like tuner, like, for example: > > config MEDIA_TUNER_TDA827X > tristate "Philips TDA827X silicon tuner" > depends on VIDEO_MEDIA && I2C > default m if MEDIA_TUNER_CUSTOMISE > > > So, for example, we want > > to put the ak881x video encoder driver under > > > > comment "Video encoders" > > > > and those drivers are only visible if VIDEO_HELPER_CHIPS_AUTO is > > unselected, and if it is selected, which it is by default, there is noone > > to automatically select ak881x. So, I think, the proposed patch is not a > > work-around, but a reasonable solution for this issue. > > Even the menu being invisible, any of the above logic would work, if you do > something like: > > config VIDEO_AK881X > depends on ARCH_MX1 && I2C > default y if VIDEO_HELPER_CHIPS_AUTO && SOC_CAMERA > > or: > > config SOC_CAMERA > select VIDEO_AK881X if VIDEO_HELPER_CHIPS_AUTO && ARCH_MX1 Same problem here: the architecture does not determine whether this i2c driver is needed. That is determined by the board definition. I guess the right place to do this is probably in a 'mach' specific Kconfig like for example arch/arm/mach-davinci/Kconfig. But to be honest, I think that the SoC + VIDEO_HELPER_CHIPS_AUTO combination is pretty pointless. Regards, Hans > > You should just take some care, since there are some combinations that won't work. > For example, if SOC_CAMERA is a module, any ancillary drivers used by it should also > be 'm', otherwise, the driver will break. That's why, when having multiple > dependencies, the better is to use the "depends on" way. > > > > > > Thanks > > Guennadi > > --- > > Guennadi Liakhovetski, Ph.D. > > Freelance Open-Source Software Developer > > http://www.open-technology.de/ > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-media" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- Hans Verkuil - video4linux developer - sponsored by TANDBERG -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
