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Re: [patch 1/7] tty_port: allow a port to be opened with a tty that has no file handle

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On Mon, Mar 13, 2017 at 10:05:52PM +0000, okash.khawaja@gmail.com wrote:
> Allow access to TTY device from kernel. This is based on Alan Cox's patch
> (http://www.mail-archive.com/linux-kernel at vger.kernel.org/msg1215095.html),
> with description quoted below.
> 
> "tty_port: allow a port to be opened with a tty that has no file handle
> 
> Let us create tty objects entirely in kernel space.
> 
> With this a kernel created non file backed tty object could be used to handle
> data, and set terminal modes. Not all ldiscs can cope with this as N_TTY in
> particular has to work back to the fs/tty layer.
> 
> The tty_port code is however otherwise clean of file handles as far as I can
> tell as is the low level tty port write path used by the ldisc, the
> configuration low level interfaces and most of the ldiscs.
> 
> Currently you don't have any exposure to see tty hangups because those are
> built around the file layer. However a) it's a fixed port so you probably
> don't care about that b) if you do we can add a callback and c) you almost
> certainly don't want the userspace tear down/rebuild behaviour anyway.
> 
> This should however be sufficient if we wanted for example to enumerate all
> the bluetooth bound fixed ports via ACPI and make them directly available.
> 
> It doesn't deal with the case of a user opening a port that's also kernel
> opened and that would need some locking out (so it returned EBUSY if bound
> to a kernel device of some kind). That needs resolving along with how you
> "up" or "down" your new bluetooth device, or enumerate it while providing
> the existing tty API to avoid regressions (and to debug)."
> 
> Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
> 
> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

You do know this is already in 4.11-rc1, right?  Please rebase your
patch set on 4.11-rc2 at the least and resend.

thanks,

greg k-h

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[patch 0/7] staging: speakup: introduce tty-based comms okash.khawaja@gmail.com - 2017-03-13 23:10 +0100
  Re: [patch 0/7] staging: speakup: introduce tty-based comms Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-13 23:20 +0100
    Re: [patch 0/7] staging: speakup: introduce tty-based comms Samuel Thibault <samuel.thibault@ens-lyon.org> - 2017-03-13 23:30 +0100
      Re: [patch 0/7] staging: speakup: introduce tty-based comms Samuel Thibault <samuel.thibault@ens-lyon.org> - 2017-03-14 00:50 +0100
      Re: [patch 0/7] staging: speakup: introduce tty-based comms Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-14 00:50 +0100
      Re: [patch 0/7] staging: speakup: introduce tty-based comms Samuel Thibault <samuel.thibault@ens-lyon.org> - 2017-03-14 01:10 +0100
    Re: [patch 0/7] staging: speakup: introduce tty-based comms Samuel Thibault <samuel.thibault@ens-lyon.org> - 2017-03-14 01:50 +0100
      Re: [patch 0/7] staging: speakup: introduce tty-based comms Samuel Thibault <samuel.thibault@ens-lyon.org> - 2017-03-14 02:20 +0100
        Re: [patch 0/7] staging: speakup: introduce tty-based comms Rob Herring <robh@kernel.org> - 2017-03-15 15:50 +0100
          Re: [patch 0/7] staging: speakup: introduce tty-based comms Samuel Thibault <samuel.thibault@ens-lyon.org> - 2017-03-15 16:10 +0100
            Re: [patch 0/7] staging: speakup: introduce tty-based comms Samuel Thibault <samuel.thibault@ens-lyon.org> - 2017-03-22 01:10 +0100
      Re: [patch 0/7] staging: speakup: introduce tty-based comms Samuel Thibault <samuel.thibault@ens-lyon.org> - 2017-03-16 10:30 +0100
  Re: [patch 1/7] tty_port: allow a port to be opened with a tty that  has no file handle Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-13 23:20 +0100
    Re: [patch 1/7] tty_port: allow a port to be opened with a tty that  has no file handle Okash Khawaja <okash.khawaja@gmail.com> - 2017-03-13 23:40 +0100
  [patch 6/7] staging: speakup: add tty-based comms functions okash.khawaja@gmail.com - 2017-03-13 23:20 +0100
  [patch 3/7] staging: serial: add spk_io_ops struct to spk_synth okash.khawaja@gmail.com - 2017-03-13 23:20 +0100
  [patch 4/7] staging: speakup: move spk_stop_serial_interrupt into synth-specific release function okash.khawaja@gmail.com - 2017-03-13 23:20 +0100
  [patch 7/7] staging: speakup: migrate acntsa, bns, dummy and txprt to ttyio okash.khawaja@gmail.com - 2017-03-13 23:20 +0100
  [patch 2/7] staging: speakup: spk_serial_out and spk_wait_for_xmitr to take synth arg okash.khawaja@gmail.com - 2017-03-13 23:20 +0100
  [patch 1/7] tty_port: allow a port to be opened with a tty that has no file handle okash.khawaja@gmail.com - 2017-03-13 23:20 +0100
    Re: [patch 1/7] tty_port: allow a port to be opened with a tty that  has no file handle Dan Carpenter <dan.carpenter@oracle.com> - 2017-03-14 10:20 +0100
  [patch 5/7] staging: speakup: move those functions which do outgoing serial comms, into serialio.c okash.khawaja@gmail.com - 2017-03-13 23:20 +0100
  Re: [patch 0/7] staging: speakup: introduce tty-based comms Samuel Thibault <samuel.thibault@ens-lyon.org> - 2017-03-14 01:30 +0100

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