ARM: dts: bcm2711: Add pcie0 alias
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Message ID 20200226164601.20150-1-nsaenzjulienne@suse.de
State Mainlined
Commit 94f18b9b24ee4d812ebd30ff848298a9f413f07a
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Series
  • ARM: dts: bcm2711: Add pcie0 alias
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Commit Message

Nicolas Saenz Julienne Feb. 26, 2020, 4:46 p.m. UTC
Some bcm2711 revisions have different DMA constraints on the their PCIE
bus. The lower common denominator, being able to access the lower 3GB of
memory, is the default setting for now. Newer SoC revisions are able to
access the whole memory space.

Raspberry Pi 4's firmware is aware of this limitation and will correct
the PCIE's dma-ranges property if a pcie0 alias is available. So add
it.

Fixes: d5c8dc0d4c88 ("ARM: dts: bcm2711: Enable PCIe controller")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 1 +
 1 file changed, 1 insertion(+)

Comments

Phil Elwell Feb. 26, 2020, 5:17 p.m. UTC | #1
Hi Nicolas,

On 26/02/2020 16:46, Nicolas Saenz Julienne wrote:
> Some bcm2711 revisions have different DMA constraints on the their PCIE
> bus. The lower common denominator, being able to access the lower 3GB of
> memory, is the default setting for now. Newer SoC revisions are able to
> access the whole memory space.
> 
> Raspberry Pi 4's firmware is aware of this limitation and will correct
> the PCIE's dma-ranges property if a pcie0 alias is available. So add
> it.

I can confirm that this is exactly what the firmware is looking for, so

Reviewed-by: Phil Elwell <phil@raspberrypi.com>

Phil
Florian Fainelli Feb. 27, 2020, 7:29 p.m. UTC | #2
On Wed, 26 Feb 2020 17:46:00 +0100, Nicolas Saenz Julienne <nsaenzjulienne@suse.de> wrote:
> Some bcm2711 revisions have different DMA constraints on the their PCIE
> bus. The lower common denominator, being able to access the lower 3GB of
> memory, is the default setting for now. Newer SoC revisions are able to
> access the whole memory space.
> 
> Raspberry Pi 4's firmware is aware of this limitation and will correct
> the PCIE's dma-ranges property if a pcie0 alias is available. So add
> it.
> 
> Fixes: d5c8dc0d4c88 ("ARM: dts: bcm2711: Enable PCIe controller")
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> ---

Applied to devicetree/fixes, thanks!
--
Florian

Patch
diff mbox series

diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
index cb3385262705..479f6828d73f 100644
--- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
+++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
@@ -21,6 +21,7 @@  memory@0 {
 
 	aliases {
 		ethernet0 = &genet;
+		pcie0 = &pcie0;
 	};
 
 	leds {