From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Marek Vasut <marek.vasut@gmail.com>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Wolfram Sang <wsa@the-dreams.de>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH] arm64: dts: renesas: Add /soc dma-ranges
Date: Sat, 14 Sep 2019 18:33:06 +0200 [thread overview]
Message-ID: <CAMuHMdWz05ALM745tpw=AT2Q30nXvQV39JXTATYTEoTmH1TSRQ@mail.gmail.com> (raw)
In-Reply-To: <f1b11b42-99ee-0484-550e-8758ec6fa559@gmail.com>
Hi Marek,
On Sat, Sep 14, 2019 at 6:06 PM Marek Vasut <marek.vasut@gmail.com> wrote:
> On 9/9/19 1:18 PM, Geert Uytterhoeven wrote:
> > On Sat, Sep 7, 2019 at 6:16 PM Marek Vasut wrote:
> >> Add dma-ranges property into /soc node to describe the DMA capabilities
> >> of the bus. This is currently needed to translate PCI DMA ranges, which
> >> are limited to 32bit addresses.
> >
> >> --- a/arch/arm64/boot/dts/renesas/r8a7795.dtsi
> >> +++ b/arch/arm64/boot/dts/renesas/r8a7795.dtsi
> >> @@ -330,6 +330,7 @@
> >> #address-cells = <2>;
> >> #size-cells = <2>;
> >> ranges;
> >> + dma-ranges = <0 0x40000000 0 0x40000000 0 0xc0000000>;
> >
> > Shouldn't the length be 0x80000000 (for all SoCs)?
>
> Or should that match the amount of DRAM below 32bit boundary ?
Which is 0x80000000, according to the memory area section for the
various R-Car Gen3 SoCs.
> > Or should we allow DMA to internal System RAM, too?
>
> I think we should include SRAM, yes.
So that needs a separate range.
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:[~2019-09-14 16:33 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-07 16:16 [PATCH] arm64: dts: renesas: Add /soc dma-ranges marek.vasut
2019-09-09 8:19 ` Geert Uytterhoeven
2019-09-09 8:42 ` Marek Vasut
2019-09-09 9:05 ` Geert Uytterhoeven
2019-09-09 9:12 ` Marek Vasut
2019-09-09 11:18 ` Geert Uytterhoeven
2019-09-14 15:53 ` Marek Vasut
2019-09-14 16:33 ` Geert Uytterhoeven [this message]
2019-09-14 16:45 ` Marek Vasut
2019-09-15 13:11 ` Geert Uytterhoeven
2019-09-13 15:14 ` Rob Herring
2019-09-14 15:50 ` Marek Vasut
2019-09-23 22:33 ` Rob Herring
2019-09-26 20:02 ` Marek Vasut
2019-09-30 12:42 ` Marek Vasut
2019-09-30 15:08 ` Rob Herring
2019-09-30 15:38 ` Marek Vasut
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