Re: 答复: [PATCH] USB: storage: fix Huawei mode switching regression

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Mar 06, 2013 at 01:34:44AM +0000, Linlei (Lei Lin) wrote:
> Hello Mork,
> 
> >> ------ Because in the embedded linux system, Android, or Chrome OS, 
> >> etc. They don't integrate userspace usb_modeswitch utility for 
> >> switching.
> 
> >Why not?  If they can upgrade the kernel, then they most certainly can install a userspace utility.
> 
> >There is no excuse for an embedded system to do this differently.
> >Please see e.g. OpenWRT as an example of an embedded system doing this correctly.
> 
> But currently Android and Chrome OS has not integrated the
> usb_modeswitch utility.

That is not a kernel problem.  I find it hard to believe that Chrome OS
would not gladly accept code to resolve this issue, can't you put it
into the modemmanager or whatever Chrome OS uses to handle their
wireless modems?

As for Android, sorry, you are on your own, you will just have to deal
with the individual OEMs that are incorporating your hardware :(

> From a vendor's point of view, our purpose is to make our devices be
> supported natively by those OS.

We have a solution, usb_modeswitch, any user should be using that.

> So we consider that add the switch function to the kernel resolves the
> problem from the source.
> Then this function will be inherited by Android & Chrome OS.

Don't circumvent horribly governed userspace projects by getting changes
into the Linux kernel.  Go fix those projects instead.

Good luck,

greg k-h