Re: LDP and comedi

On Thursday 25 October 2007 05:08, Herman Bruyninckx wrote:
> BTW, what are, in the opinion of the Comedi users/developers, the real
> 'showstoppers' to move to "1.0"...?

The remaining issues I can think of:

First, the protocol for doing output commands needs to be changed (again).  
The current scheme of doing: "command, load buffer, internal trigger" 
doesn't translate to support external triggers.  We need "command, load 
buffer, arm".  Then for start_src=TRIG_NOW the command would start 
immeditately upon arming, analogously to how start_src=TRIG_INT works now.  
For start_src=TRIG_EXT, the arm step would allow the analog output fifo to 
be loaded or dma transfer initiated, and the board configured to start on 
the external trigger input.

Second, we lack support for having a subdevice that can do both input and 
output commands.  I believe the NI m-series boards can do input and output 
dio commands simultaneously, but the driver only supports output commands 
at the moment (because that's what I happened to need).   The dio 
subdevice on the ni_pcidio driver only supports input commands, although 
the hardware can do output too (not sure if it can do them simultaneously 
with input).

Third, it would be nice to have a better mechanism in place for adding 
extensions than INSN_CONFIG.

Fourth, make better use of devices' plug-n-play capabilities, and better 
hotplug/udev support.  In short removing much of the need for 
comedi_config for plug-n-play boards.

Then there's the more philosophical question of what "1.0" means.  The 
version number on comedilib is going to increment to 1.0.0 the next time 
any deprecated function is removed from the library, due to the 
current:revision:age versioning convention.  But that's not particularly 
interesting, and what I understand you to really mean is "when are we 
going to commit to freezing the interface and supporting it as it stands 
long-term."

That would mean branching, which I don't really see us as having the 
developer resources to support.  There are only a handful of people who 
contribute to comedi with any regularity.  So I would say "1.0" happens 
when we run out of things we want to improve, or the developer base 
increases significantly.

-- 
Frank