[question] between probe() and open()

[elezegarcia@gmail.com (Ezequiel García)]

Hello,

This is a question in general about usb drivers and
in particular about easycap driver.

Is there any way a driver can be accesed
between after usb_probe() but before device open()?
I guess not, since any further operation on
the device needs a struct file pointer, i.e. a file descriptor on
the user side.

In particular:
easycap driver currently calls reset() on usb_probe(),
reset() does some hardware initialization among other stuff.
However, the reset() is called once again on open().
This seems redundant, right?

The reset() is a heavy function since it access the hardware, so
it would be benefitial to change it,
but I would like someone to ack this, since it is not so trivial.

Some measures on the device shows how heavy the reset() is:

# calling reset() on usb_probe()
time modprobe easycap

real    0m1.516s
user    0m0.000s
sys     0m0.009s

---

# not calling reset() on usb_probe()
time modprobe easycap

real    0m0.003s
user    0m0.000s
sys     0m0.002s

Thanks,
Ezequiel.