From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1754678Ab1JRKqf (ORCPT <rfc822;w@1wt.eu>);
	Tue, 18 Oct 2011 06:46:35 -0400
Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:34277 "EHLO
	www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org
	with ESMTP id S1750823Ab1JRKqe (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Tue, 18 Oct 2011 06:46:34 -0400
Date: Tue, 18 Oct 2011 11:45:18 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Rob Clark <rob.clark@linaro.org>
Cc: Hugh Dickins <hughd@google.com>,
        Patrik Jakobsson <patrik.r.jakobsson@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Christoph Hellwig <hch@infradead.org>, greg@kroah.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 34/49] gma500: the GEM and GTT code is device
 independant
Message-ID: <20111018114518.5610a8c2@lxorguk.ukuu.org.uk>
In-Reply-To: <CAN_cFWP9jOGTPuoXQaXan_P1AKYrbvfLoB8hzG-YdCddfsu3Vw@mail.gmail.com>
References: <20110705141038.23872.55303.stgit@localhost.localdomain>
	<20110705144140.23872.86541.stgit@localhost.localdomain>
	<alpine.LSU.2.00.1107071742250.10362@sister.anvils>
	<20110708093859.299958df@lxorguk.ukuu.org.uk>
	<alpine.LSU.2.00.1107080917430.1781@sister.anvils>
	<20110711172517.46907e62@lxorguk.ukuu.org.uk>
	<alpine.LSU.2.00.1107111033440.1752@sister.anvils>
	<CAMeQTsb7ZMbyt8avYNOiBssERmk6vEbg7RR6TQw7CaD55MK22A@mail.gmail.com>
	<alpine.LSU.2.00.1110101102330.21957@sister.anvils>
	<CAN_cFWNkYGSajh7eG1qK+A5tWSHNR2gH4EPiPg9tKd+yw8nRYQ@mail.gmail.com>
	<alpine.LSU.2.00.1110171031290.2545@sister.anvils>
	<20111017223928.4d5ed2c6@lxorguk.ukuu.org.uk>
	<alpine.LSU.2.00.1110171528520.6878@sister.anvils>
	<CAN_cFWP9jOGTPuoXQaXan_P1AKYrbvfLoB8hzG-YdCddfsu3Vw@mail.gmail.com>
X-Mailer: Claws Mail 3.7.9 (GTK+ 2.24.4; x86_64-redhat-linux-gnu)
Face: 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
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

> What troubles could you see for swap+uncached (or more likely,
> writecombine) pages?

That should never occur. I would argue the driver is responsible for
putting the cache state of the page back sensibly before it unpins it.
That's a simple enough rule and one I think all the drivers follow at
this point.

Alan