Date: Sun, 9 Jul 2017 13:57:45 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Okash Khawaja <okash.khawaja@gmail.com>
Cc: Jiri Slaby <jslaby@suse.com>,
        Samuel Thibault <samuel.thibault@ens-lyon.org>,
        Alan Cox <gnomes@lxorguk.ukuu.org.uk>, linux-kernel@vger.kernel.org,
        devel@driverdev.osuosl.org, Kirk Reiser <kirk@reisers.ca>,
        Chris Brannon <chris@the-brannons.com>, speakup@linux-speakup.org
Subject: Re: [patch 0/3] Re: tty contention resulting from tty_open_by_device
 export
Message-ID: <20170709115745.GC14769@kroah.com>
References: <20170708083803.GA23080@kroah.com>
 <20170709114153.157783481@gmail.com>
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On Sun, Jul 09, 2017 at 12:41:53PM +0100, Okash Khawaja wrote:
> On Sat, Jul 08, 2017 at 10:38:03AM +0200, Greg Kroah-Hartman wrote:
> > Overall, the idea looks sane to me.  Keeping userspace from opening a
> > tty that the kernel has opened internally makes sense, hopefully
> > userspace doesn't get too confused when that happens.  I don't think we
> > normally return -EBUSY from an open call, have you seen what happens
> > with apps when you do this (like minicom?)
> >
> I tested this wil minincom, picocom and commands like "echo foo >
> /dev/ttyS0". They all correctly report "Device or resource busy".
> 
> I have addressed all the comments you made. I have also split the patch
> into three. Following is summary of each.
> 
> Patch 1: introduces the tty_kopen function and checks for TTY_KOPENED
> Patch 2: updates speakup code to use tty_kopen instead of
>         tty_open_by_driver
> Patch 3: reverses the export of tty_open_by_driver

Looks great, only one tiny comment about the return value from me, and
really, it's not a big deal at all, you can send a patch 4/3 to change
that up if you want.  No one really runs without the tty layer enabled :)

If there are no other objections, I'll queue this up after 4.13-rc1 is
out, nice job.

greg k-h