RE: [PATCH 1/1] tty: n_gsm: make n_gsm line number configurable

[Starke, Daniel]

> > Currently, the n_gsm line number and its derived virtual ttys are 
> > assigned in the order of allocations with no means to change this.
> 
> Which is fine, why do you need this to be changed?  What relies on specific
> line numbers in userspace that can not handle things correctly with the
> normal userspace tools we have for this type of thing?
> 
> > Introduce additional ioctl parameters numValid and num to configure 
> > the line number to allow predictable virtual tty allocation and numbering.
> > Especially when using multiple n_gsm instances at the same time.
> 
> Ick, please no.  That should never be needed, the kernel number and name
> can be anything random (and people have suggested that we do make them
> random at times).  Don't hard-code numbers in your userspace tools, that
> is just wrong.

Thank you for your feedback and review. I understand your points.
Please discard this patch.

> > --- a/include/uapi/linux/gsmmux.h
> > +++ b/include/uapi/linux/gsmmux.h
> > @@ -19,7 +19,9 @@ struct gsm_config
> >  	unsigned int mtu;
> >  	unsigned int k;
> >  	unsigned int i;
> > -	unsigned int unused[8];		/* Padding for expansion without
> > +	unsigned short numValid;
> > +	unsigned short num;
> 
> This would never work anyway (hint "short" is not a valid uapi data
> type...)

I am surprised about this as gsm_netconfig already uses unsigned short.

Best regards,
Daniel Starke