[linux-usb-devel] Option driver enhancement

Matthias Urlichs smurf at smurf.noris.de
Thu Oct 4 22:54:10 UTC 2007


Kevin Lloyd:
> I think you might be talking about the sierra.c (which was actually
> cloned from the airprime.c driver)?

No. Sierra was cloned from Option. Airprime was written by GregKH
and looks totally different, except that it should be really trivial
to get the airprime devices supported by the Option driver instead. ;-)

> In a perfect world I agree, it would be great to unify the drivers.
> However Sierra is slowly but surely adding more and more proprietary
> feature support (e.g., USB vendor specific commands, change in end-point
> support, etc.). Granted this still could all be maintained in a single
> driver it will likely get _very_ ugly.
Bah. We should talk with them about how best to handle that. Having GSM
drivers with disparate features is not a good idea.

Actually, I dunno about the "very ugly" part. sierra.c has quite a few
changes which IMHO should either have been propagated to option.c, or
not been made at all; in addition, there are a couple of semi-documented
setup messages et al., which can easily be handled by a couple of
device-specific parameters or flags. <Trying to wean myself from using
the term "blacklist" here, 'cause it isn't.>

In fact, if you look at some other drivers which implement the sort of
switch-behavior-by-device-ID which I'm proposing for option.c, you'll
see that there's *far* worse stuff than that in the kernel. :-/

Anyway, there's also stuff like the out-of-tree nozomi driver. We need
to try to bring/keep their interfaces in sync as far as possible.

For instance, I would like to see *one* way to determine that somebody
just connected a GSM modem and that the /dev/ttyWHATEVER device is its
primary comm port. udev/HAL rules which trigger on driver names or
similar nonsense just don't cut it.

> This is not to say we shouldn't encourage collaboration with each other,
> esp. with throughput issues, those will likely affect all drivers
> similarly.

Matthias Urlichs   |   {M:U} IT Design @ m-u-it.de   |  smurf at smurf.noris.de
Disclaimer: The quote was selected randomly. Really. | http://smurf.noris.de
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