On Thu 13 September 2012 03:24:53 Laurent Pinchart wrote:
> Hi Hans,
>
> Thanks for the patch.
>
> On Friday 07 September 2012 15:29:05 Hans Verkuil wrote:
> > From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> >
> > During the 2012 Media Workshop it was decided that bus_info as returned
> > by VIDIOC_QUERYCAP can no longer be empty. It should be a unique identifier,
> > and empty strings are obviously not unique.
> >
> > Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> > ---
> > Documentation/DocBook/media/v4l/vidioc-querycap.xml | 14 ++++++++++----
> > 1 file changed, 10 insertions(+), 4 deletions(-)
> >
> > diff --git a/Documentation/DocBook/media/v4l/vidioc-querycap.xml
> > b/Documentation/DocBook/media/v4l/vidioc-querycap.xml index
> > f33dd74..d5b1248 100644
> > --- a/Documentation/DocBook/media/v4l/vidioc-querycap.xml
> > +++ b/Documentation/DocBook/media/v4l/vidioc-querycap.xml
> > @@ -90,11 +90,17 @@ ambiguities.</entry>
> > <entry>__u8</entry>
> > <entry><structfield>bus_info</structfield>[32]</entry>
> > <entry>Location of the device in the system, a
> > -NUL-terminated ASCII string. For example: "PCI Slot 4". This
> > +NUL-terminated ASCII string. For example: "PCI:0000:05:06.0". This
> > information is intended for users, to distinguish multiple
> > -identical devices. If no such information is available the field may
> > -simply count the devices controlled by the driver, or contain the
> > -empty string (<structfield>bus_info</structfield>[0] = 0).<!-- XXX
> > pci_dev->slot_name example --></entry>
> > +identical devices. If no such information is available the field must
> > +simply count the devices controlled by the driver ("vivi-000"). The
> > bus_info
> > +must start with "PCI:" for PCI boards, "PCIe:" for PCI Express boards,
> > +"usb-" for USB devices, "I2C:" for i2c devices, "ISA:" for ISA devices and
> > +"parport" for parallel port devices.
>
> What about being a bit more precise than that ? We could specify what API
> drivers must use to fill the bus_info field. For instance, for USB devices,
> usb_make_path() is currently used by most drivers (which, by the way, doesn't
> return a string that starts with "USB:").
I thought about that, but should that be defined in the spec? I'm not sure
if that's the right place.
Regards,
Hans
--
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
