Re: [PATCH] Documentation: usb: serial: fixed how to provide vendor and product id

[Johan Hovold <johan@kernel.org>]

On Thu, Apr 02, 2015 at 04:25:50PM +0200, Dr. H. Nikolaus Schaller wrote:

> >>>> But it is outdated. The parameters vendor= and product= are no longer
> >>>> available since ca. 3.12 which means that documentation is lagging behind
> >>>> quite some time.
> >>> 
> >>> This is simply not true. The vendor and module parameters are still
> >>> there for usbserial (i.e. the generic driver).
> >>> 
> >>> Would you mind updating this patch to document the sysfs-method as an
> >>> alternative instead? Using sysfs is preferred as that functionality can
> >>> be used with any usb-serial driver and the drivers can also be compiled
> >>> in.
> >> 
> >> Hm. For me it did not work as described and therefore I searched for
> >> and found the solution cited below, which appears to confirm that it does
> >> not work any more. Only with these hints to use the /sys approach I
> >> could make it working immediately.
> >> 
> >> Therefore I assumed that the documentation is outdated.
> >> 
> >> But it might also be a hidden bug with the parameter passing.
> >> I had tested on 4.0-rc3.
> >> 
> >> I can try a little more but it might be waste of time to find out why the old
> >> does not work, if there is a preferred method now.
> > 
> > Please do try to figure out if it doesn't work as we have not deprecated
> > this functionality yet. It should still work.
> 
> Good news:
> 
> I have tried again (this time with 4.0-rc5) and was successful. I have no
> clue why it did not work with my tests with 4.0-rc3.

Great.
 
> So we will edit the patch to describe
> * that the sysfs method is in addition, and preferred
> * and works even if driver is compiled into the kernel (which I
> haven’t tested in my setup but assume it works as well)
> 
> Ok?

That should do it (and, yes, it works when the module is compiled in).

Thanks,
Johan