Mauro Carvalho Chehab wrote:
> Michael Krufky wrote:
>> On Fri, Dec 4, 2009 at 3:02 PM, VDR User <> wrote:
>>> No activity in this thread for 2 weeks now.  Has there been any progress?
>> I have stated that I like Manu's proposal, but I would prefer that the
>> get_property (s2api) interface were used, because it totally provides
>> an interface that is sufficient for this feature.
> I've ported Manu's proposal to S2API way of handling it. It is just compiled
> only. I haven't test it yet on a real driver.
> Comments?
> ---
> Add support for frontend statistics via S2API
> The current DVB V3 API to handle statistics has two issues:
>       - Retrieving several values can't be done atomically;
>       - There's no indication about scale information.
> This patch solves those two issues by adding a group of S2API
> that handles the needed statistics operations. It basically ports the
> proposal of Manu Abraham <> To S2API.
> As the original patch, both of the above issues were addressed.
> In order to demonstrate the changes on an existing driver for the new API, 
> I've
> implemented it at the cx24123 driver.
> There are some advantages of using this approach over using the static structs
> of the original proposal:
>       - userspace can select an arbitrary number of parameters on his get 
> request;
>       - the latency to retrieve just one parameter is lower than retrieving
> several parameters. On the cx24123 example, if user wants just signal 
> strength,
> the latency is the same as reading one register via i2c bus. If using the 
> original
> proposal, the latency would be 6 times worse, since you would need to get 3 
> properties
> at the same time;
>       - the latency for reading all 3 parameters at the same time is equal to
> the latency of the original proposal;
>       - if newer statistics parameters will be needed in the future, it is 
> just
> a matter of adding additional S2API command/value pairs;
>       - the DVB V3 calls can be easily implemented as a call to the new 
> get_stats ops,
> without adding extra latency time.

In time:

I only wrote the get callback. It could be interesting to implement also the 
set callback
for the DTV_FE*_UNIT parameters if there are some cases where the same driver 
can provide
a different set of units/parameters. This way, it is possible for userspace to
negotiate what parameter type he wants, on such drivers.
> Thanks to Manu Abraham <> for his initial proposal.

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