[PATCH] ARM: dts: bcm2711-rpi-4-b: Fix pcie0's unit address

[PATCH] ARM: dts: bcm2711-rpi-4-b: Fix pcie0's unit address

[Nicolas Saenz Julienne]

dtbs_check currently complains that:

arch/arm/boot/dts/bcm2711-rpi-4-b.dts:220.10-231.4: Warning
(pci_device_reg): /scb/pcie@7d500000/pci@1,0: PCI unit address format
error, expected "0,0"

Unsurprisingly pci@0,0 is the right address, as illustrated by its reg
property:

	&pcie0 {
		pci@0,0 {
			/*
			 * As defined in the IEEE Std 1275-1994 document,
			 * reg is a five-cell address encoded as (phys.hi
			 * phys.mid phys.lo size.hi size.lo). phys.hi
			 * should contain the device's BDF as 0b00000000
			 * bbbbbbbb dddddfff 00000000. The other cells
			 * should be zero.
			 */
			reg = <0 0 0 0 0>;
		};
	};

The bus is clearly 0. So fix it.

Fixes: 258f92d2f840 ("ARM: dts: bcm2711: Add reset controller to xHCI node")
Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
---
 arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
index f24bdd0870a5..8a77f9e942be 100644
--- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
+++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
@@ -217,7 +217,7 @@ phy1: ethernet-phy@1 {
 };
 
 &pcie0 {
-	pci@1,0 {
+	pci@0,0 {
 		#address-cells = <3>;
 		#size-cells = <2>;
 		ranges;
-- 
2.31.1

Re: [PATCH] ARM: dts: bcm2711-rpi-4-b: Fix pcie0's unit address

[Rob Herring]

On Mon, Aug 30, 2021 at 12:39:09PM +0200, Nicolas Saenz Julienne wrote:
> dtbs_check currently complains that:
> 
> arch/arm/boot/dts/bcm2711-rpi-4-b.dts:220.10-231.4: Warning
> (pci_device_reg): /scb/pcie@7d500000/pci@1,0: PCI unit address format
> error, expected "0,0"
> 
> Unsurprisingly pci@0,0 is the right address, as illustrated by its reg
> property:
> 
> 	&pcie0 {
> 		pci@0,0 {
> 			/*
> 			 * As defined in the IEEE Std 1275-1994 document,
> 			 * reg is a five-cell address encoded as (phys.hi
> 			 * phys.mid phys.lo size.hi size.lo). phys.hi
> 			 * should contain the device's BDF as 0b00000000
> 			 * bbbbbbbb dddddfff 00000000. The other cells
> 			 * should be zero.
> 			 */
> 			reg = <0 0 0 0 0>;
> 		};
> 	};
> 
> The bus is clearly 0. So fix it.

s/bus/device/

The unit-address format is '<device>,<function>' (and function is 
optional). The bus number is not part of the unit-address because that 
is dynamic and then the path would not be fixed/known. The bus is part 
of 'reg' for true OpenFirmware, but for FDT I think it should always be 
0 as the DT is static. 

Looks like the child node is wrong (both unit-address and reg) as well:

                usb@1,0 {
                        reg = <0x10000 0 0 0 0>;
                        resets = <&reset RASPBERRYPI_FIRMWARE_RESET_ID_USB>;
                };

It doesn't warn because the bridge node is also missing 'device_type = 
"pci";'.

This is all fairly hard to get right (see recent hikey970 patches for a 
complex example). I'm thinking about writing a tool that generates a DT 
with PCI nodes by reading the PCI hierachy from sysfs.

Rob

Re: [PATCH] ARM: dts: bcm2711-rpi-4-b: Fix pcie0's unit address

[nsaenzju]

On Mon, 2021-08-30 at 08:39 -0500, Rob Herring wrote:
> On Mon, Aug 30, 2021 at 12:39:09PM +0200, Nicolas Saenz Julienne wrote:
> > dtbs_check currently complains that:
> > 
> > arch/arm/boot/dts/bcm2711-rpi-4-b.dts:220.10-231.4: Warning
> > (pci_device_reg): /scb/pcie@7d500000/pci@1,0: PCI unit address format
> > error, expected "0,0"
> > 
> > Unsurprisingly pci@0,0 is the right address, as illustrated by its reg
> > property:
> > 
> > 	&pcie0 {
> > 		pci@0,0 {
> > 			/*
> > 			 * As defined in the IEEE Std 1275-1994 document,
> > 			 * reg is a five-cell address encoded as (phys.hi
> > 			 * phys.mid phys.lo size.hi size.lo). phys.hi
> > 			 * should contain the device's BDF as 0b00000000
> > 			 * bbbbbbbb dddddfff 00000000. The other cells
> > 			 * should be zero.
> > 			 */
> > 			reg = <0 0 0 0 0>;
> > 		};
> > 	};
> > 
> > The bus is clearly 0. So fix it.
> 
> s/bus/device/
> 
> The unit-address format is '<device>,<function>' (and function is 
> optional). The bus number is not part of the unit-address because that 
> is dynamic and then the path would not be fixed/known. The bus is part 
> of 'reg' for true OpenFirmware, but for FDT I think it should always be 
> 0 as the DT is static. 
> 
> Looks like the child node is wrong (both unit-address and reg) as well:
> 
>                 usb@1,0 {
>                         reg = <0x10000 0 0 0 0>;
>                         resets = <&reset RASPBERRYPI_FIRMWARE_RESET_ID_USB>;
>                 };
> 
> It doesn't warn because the bridge node is also missing 'device_type = 
> "pci";'.
> 
> This is all fairly hard to get right (see recent hikey970 patches for a 
> complex example). I'm thinking about writing a tool that generates a DT 
> with PCI nodes by reading the PCI hierachy from sysfs.

Thanks for the review, I'll fix all those. That tool would be very helpful.

-- 
Nicolás Sáenz

Re: [PATCH] ARM: dts: bcm2711-rpi-4-b: Fix pcie0's unit address

[nsaenzju]

On Mon, 2021-08-30 at 08:39 -0500, Rob Herring wrote:
> On Mon, Aug 30, 2021 at 12:39:09PM +0200, Nicolas Saenz Julienne wrote:
> > dtbs_check currently complains that:
> > 
> > arch/arm/boot/dts/bcm2711-rpi-4-b.dts:220.10-231.4: Warning
> > (pci_device_reg): /scb/pcie@7d500000/pci@1,0: PCI unit address format
> > error, expected "0,0"
> > 
> > Unsurprisingly pci@0,0 is the right address, as illustrated by its reg
> > property:
> > 
> > 	&pcie0 {
> > 		pci@0,0 {
> > 			/*
> > 			 * As defined in the IEEE Std 1275-1994 document,
> > 			 * reg is a five-cell address encoded as (phys.hi
> > 			 * phys.mid phys.lo size.hi size.lo). phys.hi
> > 			 * should contain the device's BDF as 0b00000000
> > 			 * bbbbbbbb dddddfff 00000000. The other cells
> > 			 * should be zero.
> > 			 */
> > 			reg = <0 0 0 0 0>;
> > 		};
> > 	};
> > 
> > The bus is clearly 0. So fix it.
> 
> s/bus/device/
> 
> The unit-address format is '<device>,<function>' (and function is 
> optional). The bus number is not part of the unit-address because that 
> is dynamic and then the path would not be fixed/known. The bus is part 
> of 'reg' for true OpenFirmware, but for FDT I think it should always be 
> 0 as the DT is static. 
> 
> Looks like the child node is wrong (both unit-address and reg) as well:
> 
>                 usb@1,0 {
>                         reg = <0x10000 0 0 0 0>;
>                         resets = <&reset RASPBERRYPI_FIRMWARE_RESET_ID_USB>;
>                 };
> 
> It doesn't warn because the bridge node is also missing 'device_type = 
> "pci";'.
> 
> This is all fairly hard to get right (see recent hikey970 patches for a 
> complex example). I'm thinking about writing a tool that generates a DT 
> with PCI nodes by reading the PCI hierachy from sysfs.

Just to double-check I understood everything, with:

	lspci -D -PP
	0000:00:00.0 PCI bridge: Broadcom Inc. and subsidiaries BCM2711 PCIe Bridge (rev 10)
	0000:00:00.0/01:00.0 USB controller: VIA Technologies, Inc. VL805/806 xHCI USB 3.0 Controller (rev 01)

It should look like this:

	&pcie0 {
		pci@0,0 {
			device_type = "pci";
			#address-cells = <3>;
			#size-cells = <2>;
			ranges;

			reg = <0 0 0 0 0>;

			usb@0,0 {
				reg = <0 0 0 0 0>;
				resets = <&reset RASPBERRYPI_FIRMWARE_RESET_ID_USB>;
			};
		};
	};

Thanks!

-- 
Nicolás Sáenz

Re: [PATCH] ARM: dts: bcm2711-rpi-4-b: Fix pcie0's unit address

[Rob Herring]

On Mon, Aug 30, 2021 at 11:45 AM <nsaenzju@redhat.com> wrote:
>
> On Mon, 2021-08-30 at 08:39 -0500, Rob Herring wrote:
> > On Mon, Aug 30, 2021 at 12:39:09PM +0200, Nicolas Saenz Julienne wrote:
> > > dtbs_check currently complains that:
> > >
> > > arch/arm/boot/dts/bcm2711-rpi-4-b.dts:220.10-231.4: Warning
> > > (pci_device_reg): /scb/pcie@7d500000/pci@1,0: PCI unit address format
> > > error, expected "0,0"
> > >
> > > Unsurprisingly pci@0,0 is the right address, as illustrated by its reg
> > > property:
> > >
> > >     &pcie0 {
> > >             pci@0,0 {
> > >                     /*
> > >                      * As defined in the IEEE Std 1275-1994 document,
> > >                      * reg is a five-cell address encoded as (phys.hi
> > >                      * phys.mid phys.lo size.hi size.lo). phys.hi
> > >                      * should contain the device's BDF as 0b00000000
> > >                      * bbbbbbbb dddddfff 00000000. The other cells
> > >                      * should be zero.
> > >                      */
> > >                     reg = <0 0 0 0 0>;
> > >             };
> > >     };
> > >
> > > The bus is clearly 0. So fix it.
> >
> > s/bus/device/
> >
> > The unit-address format is '<device>,<function>' (and function is
> > optional). The bus number is not part of the unit-address because that
> > is dynamic and then the path would not be fixed/known. The bus is part
> > of 'reg' for true OpenFirmware, but for FDT I think it should always be
> > 0 as the DT is static.
> >
> > Looks like the child node is wrong (both unit-address and reg) as well:
> >
> >                 usb@1,0 {
> >                         reg = <0x10000 0 0 0 0>;
> >                         resets = <&reset RASPBERRYPI_FIRMWARE_RESET_ID_USB>;
> >                 };
> >
> > It doesn't warn because the bridge node is also missing 'device_type =
> > "pci";'.
> >
> > This is all fairly hard to get right (see recent hikey970 patches for a
> > complex example). I'm thinking about writing a tool that generates a DT
> > with PCI nodes by reading the PCI hierachy from sysfs.
>
> Just to double-check I understood everything, with:
>
>         lspci -D -PP
>         0000:00:00.0 PCI bridge: Broadcom Inc. and subsidiaries BCM2711 PCIe Bridge (rev 10)
>         0000:00:00.0/01:00.0 USB controller: VIA Technologies, Inc. VL805/806 xHCI USB 3.0 Controller (rev 01)
>
> It should look like this:
>
>         &pcie0 {
>                 pci@0,0 {
>                         device_type = "pci";
>                         #address-cells = <3>;
>                         #size-cells = <2>;
>                         ranges;
>
>                         reg = <0 0 0 0 0>;
>
>                         usb@0,0 {
>                                 reg = <0 0 0 0 0>;
>                                 resets = <&reset RASPBERRYPI_FIRMWARE_RESET_ID_USB>;
>                         };
>                 };
>         };

Yes, that looks correct.

Rob