From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
Andy Shevchenko <andy.shevchenko@gmail.com>,
Vinod Koul <vkoul@kernel.org>,
dmaengine <dmaengine@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
Linux-sh list <linux-sh@vger.kernel.org>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH 0/3] dmaengine: Stear users towards dma_request_slave_chan()
Date: Tue, 4 Feb 2020 09:01:55 +0100 [thread overview]
Message-ID: <CAMuHMdUYcSPoK8NOSdMzU_Jtg84aPMNKeGnacnF7=aidV4eqvw@mail.gmail.com> (raw)
In-Reply-To: <b09ad222-f5b8-af5a-6c2b-2dd6b30f1c73@ti.com>
Hi Peter,
On Tue, Feb 4, 2020 at 7:52 AM Peter Ujfalusi <peter.ujfalusi@ti.com> wrote:
> On 03/02/2020 22.34, Geert Uytterhoeven wrote:
> > On Mon, Feb 3, 2020 at 9:21 PM John Paul Adrian Glaubitz
> > <glaubitz@physik.fu-berlin.de> wrote:
> >> On 2/3/20 2:32 PM, Geert Uytterhoeven wrote:
> >>> Both rspi and sh-msiof have users on legacy SH (i.e. without DT):
> >>
> >> FWIW, there is a patch set by Yoshinori Sato to add device tree support
> >> for classical SuperH hardware. It was never merged, unfortunately :(.
> >
> > True.
> >
> >>> Anyone who cares for DMA on SuperH?
> >>
> >> What is DMA used for on SuperH? Wouldn't dropping it cut support for
> >> essential hardware features?
> >
> > It may make a few things slower.
>
> I would not drop DMA support but I would suggest to add dma_slave_map
> for non DT boot so the _compat() can be dropped.
Which is similar in spirit to gpiod_lookup and clk_register_clkdev(),
right?
> Imho on lower spec SoC (and I believe SuperH is) the DMA makes big
> difference offloading data movement from the CPU.
Assumed it is actually used...
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@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:[~2020-02-04 8:02 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200203101806.2441-1-peter.ujfalusi@ti.com>
[not found] ` <CAHp75Vf__isc59YBS9=O+9ApSV62XuZ2nBAWKKD_K7i72P-yFg@mail.gmail.com>
[not found] ` <e47927aa-8d40-aa71-aef4-5f9c4cbbc03a@ti.com>
[not found] ` <CAHp75Vd1A+8N_RPq3oeoXS19XeFtv7YK69H5XfzLMxWyCHbzBQ@mail.gmail.com>
[not found] ` <701ab186-c240-3c37-2c0b-8ac195f8073f@ti.com>
2020-02-03 13:32 ` [PATCH 0/3] dmaengine: Stear users towards dma_request_slave_chan() Geert Uytterhoeven
2020-02-03 20:21 ` John Paul Adrian Glaubitz
2020-02-03 20:34 ` Geert Uytterhoeven
2020-02-03 21:26 ` John Paul Adrian Glaubitz
2020-02-04 8:13 ` Geert Uytterhoeven
2020-02-04 6:52 ` Peter Ujfalusi
2020-02-04 8:01 ` Geert Uytterhoeven [this message]
2020-02-04 8:15 ` Peter Ujfalusi
2020-02-04 8:21 ` Peter Ujfalusi
2020-02-04 9:16 ` Rob Landley
2020-02-04 9:27 ` Geert Uytterhoeven
2020-02-04 10:18 ` Rob Landley
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