Quectel EG21 modem QMI connection works but MM fallbacks to ttyUSB2 as primary port

[Aleksander Morgado]

Hey Carl,

>         Quectel has lot of customers, and most of them are use system like openwrt, android, others embedded -linux.
>         and the kernel version used is usually is V3.x,V4.x.
>         it will spend very much time (for quectel-self and customers):
>                          if we appiled patch to the upstream qmi_wwan driver, and back-port the driver to the customer's kernel.
>         So we directly povide qmi_wwan_q.c, suitable for ALL kernel versions (V3.2 and later), the customers just need 'copy + paste' it.
>

That's a fair enough reason I guess. May I suggest, though, that
instead of always telling your customers to use the "qmi_wwan_q"
driver, you could tell them something like "the EC21 (0x2c7c, 0x0121)
is supported in the Linux kernel since v4.9"? Your driver should be a
fallback case when the user is using an old kernel that doesn't
support the module by default, your driver should not be the default
IMO. Keeping a list with your module versions and the kernel versions
where support was introduced would be a great source of information
for your customers ;)

-- 
Aleksander
https://aleksander.es