Re: [Mspgcc-users] [linux-usb-devel] [patch, attach, RFC] usb-serial: ti_usb removing firmware

[Al B. <alb...@st...>]

Quoting Alan Stern <st...@ro...>:

> > Mister Greg, how to change configuration _inside_ the driver? Device
> > was made to be
> > working on second usb config after one reconnect/device change, i've
> > lost whole day
> > trying to make something with that. After all, usb_set_configuration(=
)
> > isn't even
> > EXPORT()ED at all !

The current driver depends on a hot plug script to change configurations.
See the comments at the top of the file.  That is not an ideal situation
at all.  If 2.6.19 again has a way for the driver to change its configura=
tion
that would be great.

-- Al

>
> It isn't exported because, generally speaking, drivers can't use it.  I=
f
> your driver called usb_set_configuration() from within its probe routin=
e,
> it would hang.  That's because usb_set_configuration would unregister t=
he
> interface being probed by your driver, so it would try to call your
> driver's disconnect routine, but first it would have to wait for the pr=
obe
> to finish -- deadlock.
>
> There is an exported routine drivers can use in the rare cases where th=
ey
> do need to change configurations.  It's called
> usb_driver_set_configuration(), and it is present in 2.6.19.
>
> Alan Stern
>
>