Date: Wed, 14 Oct 2009 00:01:45 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Fulghum <paulkf@microgate.com>, Boyan <btanastasov@yahoo.co.uk>,
       " =?ISO-8859-14?B?RnLpZOlyaWM=?= L. W. Meunier" <fredlwm@gmail.com>,
       "Justin P. Mattock" <justinmattock@gmail.com>, Nix <nix@esperi.org.uk>,
       "Rafael J. Wysocki" <rjw@sisk.pl>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Kernel Testers List <kernel-testers@vger.kernel.org>,
       Dmitry Torokhov <dmitry.torokhov@gmail.com>, Ed Tomlinson <edt@aei.ca>,
       OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Subject: Re: [Bug #14388] keyboard under X with 2.6.31
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> And no, I'm not sure my patch helps. I'd have expected 
> 'tty_buffer_flush()' to be something very rare, for example. But I also 
> didn't really check if we may do it some other way.

It is rare for most applications

> But I _am_ sure that it makes the code a whole lot more straightforward. 
> Bits that say "we're busy flushing" suddenly actually act that way, and 
> pointers that say "this is the head of the buffers" also act that wy.

The more I look the more I think a mutex is the right answer. It also
provides us with a "stop feeding me" lock for ldisc changes and tty close
down bits.
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