Re: [PATCH 0/9] tty: tty_struct dependency clean-ups

From: Rob Herring
Date: Sun Sep 11 2016 - 23:05:39 EST


On Sun, Sep 11, 2016 at 4:14 PM, One Thousand Gnomes
<gnomes@xxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, 9 Sep 2016 17:37:01 -0500
> Rob Herring <robh@xxxxxxxxxx> wrote:
>
>> This patch series removes or prepares to remove some of the dependencies
>> on tty_struct within tty_port drivers. This will allow using tty_ports
>> directly for so called UART slave devices.
>
> You can create a tty_struct kernel side with the two tiny changes I
> posted before. Why do you want to do invasive tree wide changes when you
> can do simple ones ?

Well, I don't want to do invasive changes, but I thought the idea was
to use tty_port struct without a tty_struct.

>> Next up after this are moving some functions to the tty_port ops. I've
>> got some WIP patches for some of that, but nothing ready to send out
>> quite yet.
>
> I think before this lot happens you need to decide where these structures
> belong. Termios and termios_locked for example could live in the tty_port
> as the physical tty is incapable of having multiple sets of terminal data
> at once.

I was planning to keep termios out of tty_port and make clients of
tty_port carry it if for nothing else not quite understanding all the
details around the lifetime, init and locking of it. If there's always
a tty_struct then there's not much point moving it other than which
struct makes more sense. But that would cause some churn.

Rob