The board is equipped with a 128Mbit SDRAM.
128Mbit = 16 Mbyte = 16,777,216 bytes = 0x1000000.

Fixes: 626e7ea00215 ("ARM: DT: stm32: move dma translation to board files")
Link: https://www.st.com/en/evaluation-tools/32f469idiscovery.html
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

 arch/arm/boot/dts/st/stm32f469-disco.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/st/stm32f469-disco.dts b/arch/arm/boot/dts/st/stm32f469-disco.dts
index cbbd521bf010..f173a5892b7d 100644
--- a/arch/arm/boot/dts/st/stm32f469-disco.dts
+++ b/arch/arm/boot/dts/st/stm32f469-disco.dts
@@ -84,7 +84,7 @@ vdd_dsi: vdd-dsi {
 	};
 
 	soc {
-		dma-ranges = <0xc0000000 0x0 0x10000000>;
+		dma-ranges = <0xc0000000 0x0 0x1000000>;
 	};
 
 	leds {
-- 
2.34.1

On Mon, Sep 4, 2023, at 20:05, Dario Binacchi wrote:
> The board is equipped with a 128Mbit SDRAM.
> 128Mbit = 16 Mbyte = 16,777,216 bytes = 0x1000000.
>
> Fixes: 626e7ea00215 ("ARM: DT: stm32: move dma translation to board files")
> Link: https://www.st.com/en/evaluation-tools/32f469idiscovery.html
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
>
> ---
>
>  arch/arm/boot/dts/st/stm32f469-disco.dts | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/st/stm32f469-disco.dts 
> b/arch/arm/boot/dts/st/stm32f469-disco.dts
> index cbbd521bf010..f173a5892b7d 100644
> --- a/arch/arm/boot/dts/st/stm32f469-disco.dts
> +++ b/arch/arm/boot/dts/st/stm32f469-disco.dts
> @@ -84,7 +84,7 @@ vdd_dsi: vdd-dsi {
>  	};
> 
>  	soc {
> -		dma-ranges = <0xc0000000 0x0 0x10000000>;
> +		dma-ranges = <0xc0000000 0x0 0x1000000>;
>  	};

The dma-ranges should be independent of the installed
memory, they usually reflect the addressing capabilities
of the bus, so this patch should not be needed.

      Arnd

Hello Arnd,

On Sat, Sep 9, 2023 at 4:28 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Mon, Sep 4, 2023, at 20:05, Dario Binacchi wrote:
> > The board is equipped with a 128Mbit SDRAM.
> > 128Mbit = 16 Mbyte = 16,777,216 bytes = 0x1000000.
> >
> > Fixes: 626e7ea00215 ("ARM: DT: stm32: move dma translation to board files")
> > Link: https://www.st.com/en/evaluation-tools/32f469idiscovery.html
> > Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> >
> > ---
> >
> >  arch/arm/boot/dts/st/stm32f469-disco.dts | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/boot/dts/st/stm32f469-disco.dts
> > b/arch/arm/boot/dts/st/stm32f469-disco.dts
> > index cbbd521bf010..f173a5892b7d 100644
> > --- a/arch/arm/boot/dts/st/stm32f469-disco.dts
> > +++ b/arch/arm/boot/dts/st/stm32f469-disco.dts
> > @@ -84,7 +84,7 @@ vdd_dsi: vdd-dsi {
> >       };
> >
> >       soc {
> > -             dma-ranges = <0xc0000000 0x0 0x10000000>;
> > +             dma-ranges = <0xc0000000 0x0 0x1000000>;
> >       };
>
> The dma-ranges should be independent of the installed
> memory, they usually reflect the addressing capabilities
> of the bus, so this patch should not be needed.

Thank you for the explanation.

Question, could I then use this node to describe the installed memory?

memory@c0000000 {
            device_type = "memory";
            reg = <0xC0000000 0x1000000>;
};

I recently submitted this series to U-Boot
(https://patchwork.ozlabs.org/project/uboot/patch/20230903205703.662080-5-dario.binacchi@amarulasolutions.com/),
and I would like to allocate the framebuffer by retrieving the correct
information from the device tree, without wiring anything in the code.

Thanks and regards,

Dario

>
>       Arnd



-- 

Dario Binacchi

Senior Embedded Linux Developer

dario.binacchi@amarulasolutions.com

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