[review] New 'fibocom' plugin

[Aleksander Morgado]

On Thu, Jul 19, 2018 at 9:23 PM, Dan Williams <dcbw at redhat.com> wrote:
> On Thu, 2018-07-19 at 21:10 +0200, Aleksander Morgado wrote:
>> > On Chrome OS, we simply use ID_MM_PORT_IGNORE to ignore all AT
>> > ports
>> > on the L850-GL module (e.g.
>> > https://chromium.googlesource.com/chromiumos/overlays/chromiumos-ov
>> > erlay/+/master/net-misc/modemmanager-next/files/77-mm-fibocom-port-
>> > types.rules).
>> >
>> > The modem is functional with just MBIM and supported via the
>> > generic
>> > plugin, which is the approach we took on Chrome OS. IMHO, there is
>> > little added benefit with a new modem plugin. More importantly, AT
>> > probing takes quite some time, and I observed it often took 7
>> > seconds.
>> > We've been trying hard for some time to move everything to purely
>> > MBIM
>> > or QMI :)
>> >
>>
>> I'm going to extend this plugin in the following weeks with more
>> features that will require the use of the AT port, e.g. GPS location
>> and such. I agree that probing is a bit slow right now, but that is
>> just because the DIAG port goes first through a series of AT probing
>> steps which are not needed. For devices with fixed layouts like this
>> one, adding udev tags to specify port types isn't bad IMO, and we
>> should probably do that for the DIAG port (i.e. flag it as "not AT"
>> for example).
>
> Agreed; ideally we can begin to restrict which ports we bother probing
> for DIAG, since with QMI and MBIM DIAG is much less useful these days.
>

You may know this better than me; are all DIAG ports from all qualcomm
modems ever of the same class/subclass/protocol? i.e. Cls=ff(vend.)
Sub=ff Prot=ff
In other words, should we bother probing QCDM for ports that are not ff/ff/ff?

-- 
Aleksander
https://aleksander.es