Re: [PATCH] option: Improve Quectel EP06 detection
From: Johan Hovold
Date: Thu Sep 13 2018 - 05:18:00 EST
On Wed, Sep 12, 2018 at 10:34:43PM +0200, Bjørn Mork wrote:
> Dan Williams <dcbw@xxxxxxxxxx> writes:
> > The fact that the firmware implementation has the ability to change the
> > endpoints is unrelated to Kristian's case, and that alone is
> > justification for this to be quirked in the driver. People other than
> > Kristian will undoubtedly use the functionality, on platforms less
> > limited.
> FWIW, I agree with Dan and Kristian on this. It's a documented feature,
> and it will be used. The reasons are irrelevant. The firmware
> implementation is inconvenient, but we should still strive to make it
> Just Work in Linux. Kristian's solution does that.
> > Also most Huawei modems have the ability to change their layout and
> > configuration just like the EP06 via the U2DIAG and SETPORT commands.
> Yes, but they are nice enough to use unique class/subclass/protocol
> triplets for their functions so it's easy to support the changing
> layout. At least as long as they use their own VID and not some laptop
> The Sierra Wireless strategy, using fixed interface numbers leaving
> "holes" is another fine solution to the problem. Or they could have
> allocated unique VIDs per function combination, as long as the number of
> valid combinations are low. But they didn't. It's not like it's the
> first bad firmware design we've had to deal with. Let's just work
> around it, like we always do. No need to make life difficult for end
> users just because Quectel makes life difficult for us.
Ok, thanks for everyone for your input. As Lars I was sceptical about
this, but if this is contained to Quectel and we have a solutions which
hopefully covers all permutations for their other devices, let's go
along with this.
I'd prefer seeing this contained in the device-id table as far as
possible rather than maintaining a second table of product ids in
probe() so I've cooked up a patch (on top of this one) adding a new
device-id match flag.
Kristian would you mind giving it a try?
Oh, also note that I dropped the RSVD(5) for the ADB interface in your
patch since it uses a different subclass anyway. I'll submit both
patches in a series.