From: "Roedel, Joerg" <Joerg.Roedel@amd.com>
To: Florian Mickler <florian@mickler.org>
Cc: Andy Walls <awalls@md.metrocast.net>,
"mchehab@infradead.org" <mchehab@infradead.org>,
"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"js@linuxtv.org" <js@linuxtv.org>,
"tskd2@yahoo.co.jp" <tskd2@yahoo.co.jp>,
"liplianin@me.by" <liplianin@me.by>,
"g.marco@freenet.de" <g.marco@freenet.de>,
"aet@rasterburn.org" <aet@rasterburn.org>,
"pb@linuxtv.org" <pb@linuxtv.org>,
"mkrufky@linuxtv.org" <mkrufky@linuxtv.org>,
"nick@nick-andrew.net" <nick@nick-andrew.net>,
"max@veneto.com" <max@veneto.com>,
"janne-dvb@grunau.be" <janne-dvb@grunau.be>,
Oliver Neukum <oliver@neukum.org>,
Greg Kroah-Hartman <greg@kroah.com>,
"Rafael J. Wysocki" <rjw@sisk.pl>,
James Bottomley <James.Bottomley@HansenPartnership.com>
Subject: Re: [PATCH 0/6] get rid of on-stack dma buffers
Date: Tue, 22 Mar 2011 11:44:26 +0100 [thread overview]
Message-ID: <20110322104426.GA20444@amd.com> (raw)
In-Reply-To: <20110321220315.7545a61a@schatten.dmk.lab>
On Mon, Mar 21, 2011 at 05:03:15PM -0400, Florian Mickler wrote:
> I guess (not verified), that the dma api takes sufficient precautions
> to abort the dma transfer if a timeout happens. So freeing _should_
> not be an issue. (At least, I would expect big fat warnings everywhere
> if that were the case)
Freeing is very well an issue. All you can expect from the DMA-API is to
give you a valid DMA handle for your device. But it can not prevent that
a device uses this handle after you returned it. You need to make sure
yourself that any pending DMA is canceled before calling kfree().
Joerg
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AMD Operating System Research Center
Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach
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Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632
next prev parent reply other threads:[~2011-03-22 10:44 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-21 18:33 [PATCH 0/6] get rid of on-stack dma buffers Florian Mickler
2011-03-21 18:33 ` [PATCH 1/6] [media] a800: " Florian Mickler
2011-03-21 18:33 ` [PATCH 2/6 v2] [media] vp7045: " Florian Mickler
2011-03-21 18:33 ` [PATCH 3/6] [media] friio: " Florian Mickler
2011-03-21 18:33 ` [PATCH 4/6] [media] dw2102: get rid of on-stack dma buffer Florian Mickler
2011-03-21 18:33 ` [PATCH 5/6] [media] m920x: get rid of on-stack dma buffers Florian Mickler
2011-03-21 18:33 ` [PATCH 6/6] [media] opera1: get rid of on-stack dma buffer Florian Mickler
2011-03-21 19:26 ` [PATCH 0/6] get rid of on-stack dma buffers Andy Walls
2011-03-21 21:03 ` Florian Mickler
2011-03-22 10:44 ` Roedel, Joerg [this message]
[not found] ` <AANLkTimXobrwc-XHgoVN1dD5NCTde64dykbyvtJMo229@mail.gmail.com>
2011-03-22 13:12 ` Oliver Neukum
2011-03-22 14:27 ` Florian Mickler
2011-03-22 10:59 ` Jiri Kosina
2011-03-22 12:33 ` Johannes Stezenbach
2011-03-22 13:35 ` James Bottomley
2011-03-22 14:02 ` Florian Mickler
2011-03-22 20:15 ` David Miller
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