[PATCH v1 0/3] This series adds ethernet support for RPi4.

[PATCH v1 0/3] This series adds ethernet support for RPi4.

[matthias.bgg]

From: Matthias Brugger <mbrugger@suse.com>

Raspberry Pi 4 uses the broadcom genet chip in version five.
This chip has a dma controller integrated. Up to now the maximal
burst size was hard-coded to 0x10. But it turns out that Raspberry Pi 4
does only work with the smaller maximal burst size of 0x8.

This series adds a new optional property to the driver, dma-burst-sz.
The very same property is already used by another drivers in the kernel.


Matthias Brugger (3):
  dt-bindings: net: bcmgenet add property for max DMA burst size
  net: bcmgenet: use optional max DMA burst size property
  ARM: dts: bcm2711: Enable GENET support for the RPi4

 .../devicetree/bindings/net/brcm,bcmgenet.txt |  2 ++
 arch/arm/boot/dts/bcm2711-rpi-4-b.dts         | 22 +++++++++++++++++++
 arch/arm/boot/dts/bcm2711.dtsi                | 18 +++++++++++++++
 .../net/ethernet/broadcom/genet/bcmgenet.c    | 13 +++++++++--
 .../net/ethernet/broadcom/genet/bcmgenet.h    |  1 +
 5 files changed, 54 insertions(+), 2 deletions(-)

-- 
2.23.0

[PATCH v1 1/3] dt-bindings: net: bcmgenet add property for max DMA burst size

[matthias.bgg]

From: Matthias Brugger <mbrugger@suse.com>

The maximal usable DMA burst size can vary in different SoCs.
Add a optional property to configure the DMA channels properly.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---

 Documentation/devicetree/bindings/net/brcm,bcmgenet.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/brcm,bcmgenet.txt b/Documentation/devicetree/bindings/net/brcm,bcmgenet.txt
index 3956af1d30f3..10a7169ec902 100644
--- a/Documentation/devicetree/bindings/net/brcm,bcmgenet.txt
+++ b/Documentation/devicetree/bindings/net/brcm,bcmgenet.txt
@@ -30,6 +30,8 @@ Optional properties:
   See Documentation/devicetree/bindings/net/fixed-link.txt for information on
   the property specifics
 
+- dma-burst-sz: Maximal length of a burst.
+
 Required child nodes:
 
 - mdio bus node: this node should always be present regardless of the PHY
-- 
2.23.0

[PATCH v1 3/3] ARM: dts: bcm2711: Enable GENET support for the RPi4

[matthias.bgg]

From: Matthias Brugger <mbrugger@suse.com>

Enable Gigabit Ethernet support on the Raspberry Pi 4
Model B.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>

---

 arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 22 ++++++++++++++++++++++
 arch/arm/boot/dts/bcm2711.dtsi        | 18 ++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
index cccc1ccd19be..958553d62670 100644
--- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
+++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
@@ -97,6 +97,28 @@
 	status = "okay";
 };
 
+&genet {
+	phy-handle = <&phy1>;
+	phy-mode = "rgmii";
+	status = "okay";
+	dma-burst-sz = <0x08>;
+
+	mdio@e14 {
+		compatible = "brcm,genet-mdio-v5";
+		reg = <0xe14 0x8>;
+		reg-names = "mdio";
+		#address-cells = <0x0>;
+		#size-cells = <0x1>;
+
+		phy1: ethernet-phy@1 {
+			compatible = "ethernet-phy-ieee802.3-c22";
+			/* No PHY interrupt */
+			max-speed = <1000>;
+			reg = <0x1>;
+		};
+	};
+};
+
 /* uart0 communicates with the BT module */
 &uart0 {
 	pinctrl-names = "default";
diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
index ac83dac2e6ba..e2e837fcad59 100644
--- a/arch/arm/boot/dts/bcm2711.dtsi
+++ b/arch/arm/boot/dts/bcm2711.dtsi
@@ -305,6 +305,24 @@
 			cpu-release-addr = <0x0 0x000000f0>;
 		};
 	};
+
+	scb {
+		compatible = "simple-bus";
+		#address-cells = <2>;
+		#size-cells = <1>;
+
+		ranges = <0x0 0x7c000000  0x0 0xfc000000  0x03800000>;
+
+		genet: ethernet@7d580000 {
+			compatible = "brcm,genet-v5";
+			reg = <0x0 0x7d580000 0x10000>;
+			#address-cells = <0x1>;
+			#size-cells = <0x1>;
+			interrupts = <GIC_SPI 157 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 158 IRQ_TYPE_LEVEL_HIGH>;
+			status = "disabled";
+		};
+	};
 };
 
 &clk_osc {
-- 
2.23.0

Re: [PATCH v1 1/3] dt-bindings: net: bcmgenet add property for max DMA burst size

[Florian Fainelli]

On 10/11/19 11:48 AM, matthias.bgg@kernel.org wrote:
> From: Matthias Brugger <mbrugger@suse.com>
> 
> The maximal usable DMA burst size can vary in different SoCs.
> Add a optional property to configure the DMA channels properly.
> 
> Signed-off-by: Matthias Brugger <mbrugger@suse.com>

There are enough differences in the integration of GENET in 2711 (versus
any other STB chip where it has been used) that a brcm,bcm2711-genet-v5
compatible string would be in order. From there, you can derive the DMA
burst size without using additional properties.
-- 
Florian

Re: [PATCH v1 3/3] ARM: dts: bcm2711: Enable GENET support for the RPi4

[Florian Fainelli]

On 10/11/19 11:48 AM, matthias.bgg@kernel.org wrote:
> From: Matthias Brugger <mbrugger@suse.com>
> 
> Enable Gigabit Ethernet support on the Raspberry Pi 4
> Model B.
> 
> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
> 
> ---
> 
>  arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 22 ++++++++++++++++++++++
>  arch/arm/boot/dts/bcm2711.dtsi        | 18 ++++++++++++++++++
>  2 files changed, 40 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
> index cccc1ccd19be..958553d62670 100644
> --- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
> +++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
> @@ -97,6 +97,28 @@
>  	status = "okay";
>  };
>  
> +&genet {
> +	phy-handle = <&phy1>;
> +	phy-mode = "rgmii";

Can you check that things still work against David Miller's net-next?
Tree, in particular the BCM54213PE PHY might be matched by the BCM54210E
entry in drivers/net/phy/broadcom.c and I just fixed an issue in how
RGMII delays were configured:

https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=fea7fda7f50a6059220f83251e70709e45cc8040

This might require you to change the 'phy-mode' property to what is
appropriate.

> +	status = "okay";
> +	dma-burst-sz = <0x08>;
> +
> +	mdio@e14 {
> +		compatible = "brcm,genet-mdio-v5";
> +		reg = <0xe14 0x8>;
> +		reg-names = "mdio";
> +		#address-cells = <0x0>;
> +		#size-cells = <0x1>;
> +
> +		phy1: ethernet-phy@1 {
> +			compatible = "ethernet-phy-ieee802.3-c22";

This does not hurt, but this compatibility string is not required.

> +			/* No PHY interrupt */
> +			max-speed = <1000>;

And this property is not required either, since the PHY library will
determine the PHY's capabilities.

Other than those patches, I believe you also need something like this
(inspired by the Rpi downstream patch):

diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c
b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 970e478a9017..94d1dd5d56bf 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -273,11 +273,12 @@ int bcmgenet_mii_probe(struct net_device *dev)
        struct bcmgenet_priv *priv = netdev_priv(dev);
        struct device_node *dn = priv->pdev->dev.of_node;
        struct phy_device *phydev;
-       u32 phy_flags;
+       u32 phy_flags = 0;
        int ret;

        /* Communicate the integrated PHY revision */
-       phy_flags = priv->gphy_rev;
+       if (priv->internal_phy)
+               phy_flags = priv->gphy_rev;

        /* Initialize link state variables that bcmgenet_mii_setup() uses */
        priv->old_link = -1;

to prevent the internal PHY revision, which we stick into
phydev->dev_flags from incorrectly setting bits in
drivers/net/phy/broadcom.c. I will probably send this as a fix in the
next few hours.
-- 
Florian

Re: [PATCH v1 3/3] ARM: dts: bcm2711: Enable GENET support for the RPi4

[Stefan Wahren]

Am 11.10.19 um 20:48 schrieb matthias.bgg@kernel.org:
> From: Matthias Brugger <mbrugger@suse.com>
>
> Enable Gigabit Ethernet support on the Raspberry Pi 4
> Model B.

I asked some questions about genet to the RPi guys [1] which are
relevant to this patch (missing clocks and interrupt, MAC address
assignment) but i didn't get an answer yet.

During my tests with a similiar patch series i noticed that the driver
won't probe without a MAC address.

How does it get into DT (via U-Boot)?

[1] -
https://github.com/raspberrypi/linux/issues/3101#issuecomment-534665860

Re: [PATCH v1 3/3] ARM: dts: bcm2711: Enable GENET support for the RPi4

[Florian Fainelli]

On 10/11/19 4:09 PM, Stefan Wahren wrote:
> Am 11.10.19 um 20:48 schrieb matthias.bgg@kernel.org:
>> From: Matthias Brugger <mbrugger@suse.com>
>>
>> Enable Gigabit Ethernet support on the Raspberry Pi 4
>> Model B.
> 
> I asked some questions about genet to the RPi guys [1] which are
> relevant to this patch (missing clocks and interrupt, MAC address
> assignment) but i didn't get an answer yet.
> 
> During my tests with a similiar patch series i noticed that the driver
> won't probe without a MAC address.

Yes, that is true, we have an internal patch for that that we just
recently did, let me submit it so this does not block you.

> 
> How does it get into DT (via U-Boot)?
> 
> [1] -
> https://github.com/raspberrypi/linux/issues/3101#issuecomment-534665860
> 


-- 
Florian

Re: [PATCH v1 3/3] ARM: dts: bcm2711: Enable GENET support for the RPi4

[Stefan Wahren]

Am 12.10.19 um 01:09 schrieb Stefan Wahren:
> Am 11.10.19 um 20:48 schrieb matthias.bgg@kernel.org:
>> From: Matthias Brugger <mbrugger@suse.com>
>>
>> Enable Gigabit Ethernet support on the Raspberry Pi 4
>> Model B.
> I asked some questions about genet to the RPi guys [1] which are
> relevant to this patch (missing clocks and interrupt, MAC address
> assignment) but i didn't get an answer yet.
>
> During my tests with a similiar patch series i noticed that the driver
> won't probe without a MAC address.
>
> How does it get into DT (via U-Boot)?
Okay, the bootloader uses the ethernet0 alias for the genet DT node. So
this should also be added to the RPi 4 DTS. But i consider the MAC
randomize patch still helpful.
>
> [1] -
> https://github.com/raspberrypi/linux/issues/3101#issuecomment-534665860
>

Re: [PATCH v1 3/3] ARM: dts: bcm2711: Enable GENET support for the RPi4

[Stefan Wahren]

Hi Florian,

Am 11.10.19 um 21:31 schrieb Florian Fainelli:
> On 10/11/19 11:48 AM, matthias.bgg@kernel.org wrote:
>> From: Matthias Brugger <mbrugger@suse.com>
>>
>> Enable Gigabit Ethernet support on the Raspberry Pi 4
>> Model B.
>>
>> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
>>
>> ---
>>
>>  arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 22 ++++++++++++++++++++++
>>  arch/arm/boot/dts/bcm2711.dtsi        | 18 ++++++++++++++++++
>>  2 files changed, 40 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
>> index cccc1ccd19be..958553d62670 100644
>> --- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
>> +++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
>> @@ -97,6 +97,28 @@
>>  	status = "okay";
>>  };
>>
>> +&genet {
>> +	phy-handle = <&phy1>;
>> +	phy-mode = "rgmii";
> Can you check that things still work against David Miller's net-next?
> Tree, in particular the BCM54213PE PHY might be matched by the BCM54210E
> entry in drivers/net/phy/broadcom.c and I just fixed an issue in how
> RGMII delays were configured:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=fea7fda7f50a6059220f83251e70709e45cc8040
>
> This might require you to change the 'phy-mode' property to what is
> appropriate.

i applied your changes, kept the phy-mode above and the interfaces cames
up. But there is a lot of packet loss using ping. After applying this
downstream patch [1] the packet loss doesn't occur.

Is the packet loss a possible cause of the wrong phy-mode and mentioned
patch only a workaround?

[1] -
https://github.com/raspberrypi/linux/commit/360c8e98883f9cd075564be8a7fc25ac0785dee4

Re: [PATCH v1 3/3] ARM: dts: bcm2711: Enable GENET support for the RPi4

[Florian Fainelli]

On 10/13/2019 11:41 AM, Stefan Wahren wrote:
> Hi Florian,
> 
> Am 11.10.19 um 21:31 schrieb Florian Fainelli:
>> On 10/11/19 11:48 AM, matthias.bgg@kernel.org wrote:
>>> From: Matthias Brugger <mbrugger@suse.com>
>>>
>>> Enable Gigabit Ethernet support on the Raspberry Pi 4
>>> Model B.
>>>
>>> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
>>>
>>> ---
>>>
>>>  arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 22 ++++++++++++++++++++++
>>>  arch/arm/boot/dts/bcm2711.dtsi        | 18 ++++++++++++++++++
>>>  2 files changed, 40 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
>>> index cccc1ccd19be..958553d62670 100644
>>> --- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
>>> +++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
>>> @@ -97,6 +97,28 @@
>>>  	status = "okay";
>>>  };
>>>
>>> +&genet {
>>> +	phy-handle = <&phy1>;
>>> +	phy-mode = "rgmii";
>> Can you check that things still work against David Miller's net-next?
>> Tree, in particular the BCM54213PE PHY might be matched by the BCM54210E
>> entry in drivers/net/phy/broadcom.c and I just fixed an issue in how
>> RGMII delays were configured:
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=fea7fda7f50a6059220f83251e70709e45cc8040
>>
>> This might require you to change the 'phy-mode' property to what is
>> appropriate.
> 
> i applied your changes, kept the phy-mode above and the interfaces cames
> up. But there is a lot of packet loss using ping. After applying this
> downstream patch [1] the packet loss doesn't occur.

Packet loss is symptomatic of a mis-configured RGMII interface between
the MAC and the PHY.

> 
> Is the packet loss a possible cause of the wrong phy-mode and mentioned
> patch only a workaround?

The patch at [1] is not doing much with respect to RGMII delays, so it
will just keep whatever was configured prior to Linux taking over the
PHY. The addition of the BCM54213PE entry makes use of the
bcm54xx_config_init() callback, which does not call
bcm54xx_config_clock_delay() for the BCM54213PE PHY model, which is why
it "solves" the packet loss by preserving whatever was already configured.

I would suggest checking with the Pi folks whether 'rgmii' is really the
right mode of operation here (that is, the PHY is not adding TXC or RXC
delays at all), or it just happens to work by virtue of the PHY device
defaulting to a certain mode *and* the PHY device driver in Linux not
attempting to correctly change the RX/TX clock delays based on the
phy_interface_t value (aka: maintain the status quo).

Thanks for checking!

> 
> [1] -
> https://github.com/raspberrypi/linux/commit/360c8e98883f9cd075564be8a7fc25ac0785dee4
> 

-- 
Florian