From: geert@linux-m68k.org (Geert Uytterhoeven)
To: linux-arm-kernel@lists.infradead.org
Subject: DMA engine API issue (was: [PATCH/RFC 0/5] R-Car Gen2 DMAC hardware descriptor list support)
Date: Wed, 6 Aug 2014 09:17:57 +0200 [thread overview]
Message-ID: <CAMuHMdVz8hNus5x1hn0feqb1SYsUuhA4QHHfPGyebiKLZJwfEQ@mail.gmail.com> (raw)
In-Reply-To: <1877927.dGcJCfKbeH@avalon>
Hi Laurent,
On Wed, Aug 6, 2014 at 1:19 AM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> I actually have the opposite problem, in my case channels of physically
> separate DMA engines can be used interchangeably to serve the system's slaves.
> Using the DMA engine DT bindings, DT nodes of the slaves currently reference a
> specific DMA engine, even if they can be served by both. This leads to limited
> dynamic channel allocation capabilities (especially when taking into account
> lazy channel allocation as mentioned in another mail in this thread).
What about adding a property to the first one, referencing the second
(or the other way around, don't know what's the easiest to implement)?
dmac0: dma-controller at e6700000 {
...
renesas,alternative = <&dmac1>;
...
};
dmac1: dma-controller at e6720000 {
...
};
That would avoid having to bind a slave device explicitly to a single
dmac, or having to bind all slave devices to all dmacs.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2014-08-06 7:17 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1406032431-3807-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com>
[not found] ` <87d2cwvmxa.wl%kuninori.morimoto.gx@gmail.com>
[not found] ` <3361994.F0HgAeJkR9@avalon>
2014-07-23 11:07 ` DMA engine API issue (was: [PATCH/RFC 0/5] R-Car Gen2 DMAC hardware descriptor list support) Laurent Pinchart
2014-07-24 0:46 ` Kuninori Morimoto
2014-07-24 1:35 ` Kuninori Morimoto
2014-07-24 4:53 ` Vinod Koul
2014-07-24 4:52 ` Vinod Koul
2014-08-01 8:51 ` Laurent Pinchart
2014-08-01 14:30 ` Russell King - ARM Linux
2014-08-01 17:09 ` Vinod Koul
2014-08-04 13:47 ` Geert Uytterhoeven
2014-08-04 17:00 ` Laurent Pinchart
2014-08-04 17:54 ` Russell King - ARM Linux
2014-08-05 23:19 ` Laurent Pinchart
2014-08-06 7:17 ` Geert Uytterhoeven [this message]
2014-08-06 11:04 ` Arnd Bergmann
2014-08-01 17:07 ` Vinod Koul
2014-08-04 16:50 ` Laurent Pinchart
2014-08-04 18:03 ` DMA engine API issue Lars-Peter Clausen
2014-08-04 18:32 ` Russell King - ARM Linux
2014-08-04 23:12 ` Laurent Pinchart
2014-08-05 16:56 ` DMA engine API issue (was: [PATCH/RFC 0/5] R-Car Gen2 DMAC hardware descriptor list support) Vinod Koul
2014-07-24 12:29 ` [alsa-devel] DMA engine API issue Lars-Peter Clausen
2014-07-24 12:51 ` DMA engine API issue (was: [PATCH/RFC 0/5] R-Car Gen2 DMAC hardware descriptor list support) Russell King - ARM Linux
2014-08-01 9:24 ` Laurent Pinchart
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