[systemd-devel] Use a specific device ?

[Dan Williams]

On Thu, 2015-06-11 at 00:40 +0200, Jean-Christian de Rivaz wrote:
> Le 10. 06. 15 23:37, Bjørn Mork a écrit :
> > Jean-Christian de Rivaz <jc at eclis.ch> writes:
> >
> >> There is not so
> >> much modem manufacturers and each of them don't even release a new
> >> product range per year.
> > Ehh... I don't think we live on the same planet.  Did you know Toshiba
> > is a "modem manufacturer"? Dell? HP? There are 43 (damn - I would have
> > loved to see 42) different vendor IDs just in the option driver:
> >
> >   bjorn at nemi:/usr/local/src/git/linux$ git grep -E '^#define.*VENDOR' drivers/usb/serial/option.c |wc -l
> >   43
> 
> Please provide a complete picture:
> git grep -E '^#define.*VENDOR' drivers/usb/serial/* | wc -l
> 174
> 
> Not a such bit number. There are various vendor/product database on the 
> internet, I failed to identify a unmanageable number of modem on them.
> 
> > Feel free to start updating the whitelists in vendor specific drivers
> > like option, qcserial and qmi_wwan. Please let me know when those are
> > complete.
> >
> > No, I don't seriously expect you to do that job.  Fact is that the
> > whitelists are unmaintablable even when the scope is limited to one
> > specific mode of Qualcomm based modems.  Keeping a semi-complete
> > whitelist of all modems is not going to happen.
> >
> 
> I expected this reaction. The first problem was the fact that 
> ModemManager is unable to provide a stable name to NetworkManager 
> requiring a hack in the configuration that will not work anymore if 
> there more than a single modem. Instead of making some constructives 
> propositions to find a way to sole the problem clearly caused by 
> ModemManager, the project push all his effort to reject any critic and 

I think we all agree that the stable name thing is a problem, and in
fact I'm still open to your proposal there.

> constructive proposition. I proposed a way to make the transition to a 
> whitelist but you don't even comment on it: you seem only focused on 
> rejecting anything that can possibly fix the ModemManager problems.

But I do disagree that a whitelist is the correct way forward for modem
*identification*, which is a completely separate issue from the one
above that we all agree still needs to be solved.

Dan

> >> The 40-usb_modeswitch.rules required by some
> >> modems is not so big either.
> > There are approximately a gazillion modem IDs which do *not* need mode
> > switching.  But list size is irrelevant in any case.  See below.
> 
> So why did the list exists?
> 
> >> But most important is to understand that the current ModemManager is
> >> abusing the udev concept and confusing the users. Are you really
> >> serious when you ask a random people with a new UPS product to add a
> >> new udev rule to the ModemManager project?
> > Why do they have to do that? Their UPS should work fine even if MM
> > happens to probe it.
> 
> So why did you need blacklist in the first place? The only fact that the 
> blacklist exists is a prove that users don't want probing for non modem 
> device. The UPS is maybe not the best example, but you can't deny the 
> reality of the blacklist.
> 
> >> I think you are so focused
> >> on defending the current ModemManager abomination that you fail to see
> >> the problem from the point of view of a common user.
> > So, let's try to agree what a common user wants.  My claim is that the
> > common user wants *both* their UPS and 3G modem to work by default.
> >
> >> The length of a
> >> white list is not an excuse to not fix the problem.
> > Agreed.  The length is irrelevant. The problem is that the list will be
> > incomplete, whether it is a blacklist or whitelist. We could probably
> > discuss which one will be easiest to maintain, but that's really
> > irrelevant too. The real question is what happens to the user
> > requirements in the two cases, assuming that we don't have any prior
> > knowledge of the devices (which is very likely for any device you can
> > buy new in a store):
> >
> > whitelist:
> >   UPS works
> >   3G modem fails
> >
> > blacklist:
> >   UPS works, but is unnecessarily probed by MM
> >   3G modem works
> >
> > The choice is really simple, isn't it? MM does what it has to do.
> >
> 
> Now you have completely changed the situation that cause problem to a 
> situation where you don't see a problem. You may be happy doing this, 
> but the former problem is still there and unsolved.
> 
> Jean-Christian
> 
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