[pvrusb2] Setting "the" video standard

[Mike Isely]

One important correction....

On Sun, 23 Dec 2012, Mike Isely wrote:

   [...]

> 
> Now because the sysfs part of the pvrusb2 driver doesn't "know" all the 
> controls, it will only export what it finds.  And what's happened is 
> that within V4L that old concept of enumerated standards has gone 
> obsolete and disappeared from the V4L core.  And when that happened, I 
> removed from the pvrusb2 driver all the old logic that generated that 
> enumerated list.  The removal happened roughly coincident with the 3.0 
> kernel.  With the removal of that logic, the underlying enumeration is 
> gone and THAT is why the simple-to-understand ctl_video_standard is no 
> longer present when you're running under a recent-enough kernel.

This isn't quite correct (after further review of some old notes of 
mine).  What's happened is that the old enumeration API might actually 
still be there - but it's no longer under the control of the pvrusb2 
driver.  There was a major change a little less than a year ago where 
the pvrusb2 driver stopped directly implementing every single V4L2 API 
function.  This is in keeping with a trend throughout the V4L 
"ecosystem".  Instead, things are rearranged so that the V4L core 
implements stuff that would otherwise just be "generic" to a given 
driver, and video standard enumeration was one of those items.  Thus now 
the pvrusb2 driver no longer sees or cares about the old video standard 
enumeration functionality, and so the sysfs interface doesn't see it 
either and that's why it went away from the driver's sysfs 
implementation.

The fact now is that since the pvrusb2 driver no longer has to care 
about the old enumeration capability, that could theoretically go away 
by itself in the future (or maybe already has).  I can't tell any longer 
from within the pvrusb2 driver however since I no longer have to deal 
with it.

Sorry about that misleading bit.

  -Mike


-- 

Mike Isely
isely @ isely (dot) net
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