Re: [PATCH] tty: always relink the port

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Jan 10, 2020 at 11:08:17AM +0100, Johan Hovold wrote:
> On Fri, Dec 27, 2019 at 05:44:34PM +0000, Sudip Mukherjee wrote:
> > If the serial device is disconnected and reconnected, it re-enumerates
> > properly but does not link it. fwiw, linking means just saving the port
> > index, so allow it always as there is no harm in saving the same value
> > again even if it tries to relink with the same port.
> 
> This is a pretty vague description. Commit fb2b90014d78 ("tty: link tty
> and port before configuring it as console") completely broke usb-serial
> (and anything else hotpluggable) which obviously depends on being able
> to reuse a minor number when a new device is later plugged in after a
> disconnect.
> 
> Things are crashing left and right due to that stale port-pointer, and I
> just had to debug this only to find that this one is sitting in the
> tty-linus branch. I know, I know, Christmas and all, but would be nice
> to get it into -rc6. :)

Sorry, yes, my fault, will get to Linus either today or tomorrow.

> > Fixes: fb2b90014d78 ("tty: link tty and port before configuring it as console")
> 
> Also note that the offending commit had a stable tag unlike this one.

I'll pick it up properly, I have held off on adding the original to the
stable trees yet.

thanks,

greg k-h