Re: [PATCH 00/21] TTY buffer in tty_port and other stuff

From: Greg KH
Date: Mon Oct 22 2012 - 19:59:55 EST

On Thu, Oct 18, 2012 at 10:26:26PM +0200, Jiri Slaby wrote:
> Hi,
> this is the fifth series of patches which finally move tty buffers
> from tty_struct (present from open to close/hangup) to tty_port
> (present as long as the device). This allows us to get rid of the tty
> refcounting in the interrupt service routines and other hot paths
> after we are done. This is because we do not need to handle races
> among ISRs, timers, hangups and others, because tty_port lives as long
> as an interrupt/timer tick may occur. Unlike tty_struct.
> This set also cleans up devpts handling a bit. Devpts used to play
> with tty->driver_data which was a bit ugly. Now devpts returns a node
> which we store to driver_data and pass it back when we need devpts to
> kill that. As a result, we can do that in the pty code instead of an
> ugly hook in tty_release.
> Finally, the set moves all the n_tty private stuff from tty_struct to
> its own (internal) structure. This was an intention last time ago (at
> least here), but the races and undefined ldisc->open/close behavior
> did not allow us to do that. Now that we have ldisc kills and waits
> and bells and whistles we could finally go ahead.
> As usual, standard x86 stuff was runtime-tested. The rest is only
> checked to be compilation-errors free.

I've applied all of these, very nice.

But you broke one of the staging drivers (drivers/staging/dgrp/) Care
to fix that up now?


greg k-h
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