On Wed, 17 Mar 2010, Mauro Carvalho Chehab wrote:
> Em 17-03-2010 09:38, Guennadi Liakhovetski escreveu:
> > Helper-chip autoselection doesn't work in some situations. Add a
> > configuration
> > variable to let drivers disable it. Use it to disable autoselection if
> > SOC_CAMERA is selected.
> >
> > Signed-off-by: Guennadi Liakhovetski <[email protected]>
> > ---
> >
> > This will also be used from VOU video-output driver, other SoC drivers
> > might also want to select this option.
> >
> > drivers/media/video/Kconfig | 5 +++++
> > 1 files changed, 5 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
> > index 64682bf..73f3808 100644
> > --- a/drivers/media/video/Kconfig
> > +++ b/drivers/media/video/Kconfig
> > @@ -77,8 +77,12 @@ config VIDEO_FIXED_MINOR_RANGES
> >
> > When in doubt, say N.
> >
> > +config VIDEO_HELPER_CHIPS_AUTO_DISABLE
> > + bool
> > +
> > config VIDEO_HELPER_CHIPS_AUTO
> > bool "Autoselect pertinent encoders/decoders and other helper chips"
> > + depends on !VIDEO_HELPER_CHIPS_AUTO_DISABLE
> > default y
> > ---help---
> > Most video cards may require additional modules to encode or
> > @@ -816,6 +820,7 @@ config SOC_CAMERA
> > tristate "SoC camera support"
> > depends on VIDEO_V4L2 && HAS_DMA && I2C
> > select VIDEOBUF_GEN
> > + select VIDEO_HELPER_CHIPS_AUTO_DISABLE
> > help
> > SoC Camera is a common API to several cameras, not connecting
> > over a bus like PCI or USB. For example some i2c camera connected
> NACK.
>
> If this is not working, please fix, instead of doing a workaround.
>
> What's the exact problem?
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. 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.
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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