[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 2/3] net: bcmgenet: use optional max DMA burst size property

[matthias.bgg]

From: Matthias Brugger <mbrugger@suse.com>

Depending on the HW, the maximal usable DMA burst size can vary.
If not set accordingly a timeout in the transmit queue happens and no
package can be sent. Read to optional max-burst-sz property, if not
present, fallback to the standard value.

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

 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 13 +++++++++++--
 drivers/net/ethernet/broadcom/genet/bcmgenet.h |  1 +
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 12cb77ef1081..a7bb822a6d83 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -2576,7 +2576,8 @@ static int bcmgenet_init_dma(struct bcmgenet_priv *priv)
 	}
 
 	/* Init rDma */
-	bcmgenet_rdma_writel(priv, DMA_MAX_BURST_LENGTH, DMA_SCB_BURST_SIZE);
+	bcmgenet_rdma_writel(priv, priv->dma_max_burst_length,
+			     DMA_SCB_BURST_SIZE);
 
 	/* Initialize Rx queues */
 	ret = bcmgenet_init_rx_queues(priv->dev);
@@ -2589,7 +2590,8 @@ static int bcmgenet_init_dma(struct bcmgenet_priv *priv)
 	}
 
 	/* Init tDma */
-	bcmgenet_tdma_writel(priv, DMA_MAX_BURST_LENGTH, DMA_SCB_BURST_SIZE);
+	bcmgenet_tdma_writel(priv, priv->dma_max_burst_length,
+			     DMA_SCB_BURST_SIZE);
 
 	/* Initialize Tx queues */
 	bcmgenet_init_tx_queues(priv->dev);
@@ -3522,6 +3524,13 @@ static int bcmgenet_probe(struct platform_device *pdev)
 
 	clk_prepare_enable(priv->clk);
 
+	if (dn) {
+		of_property_read_u32(dn, "dma-burst-sz",
+				     &priv->dma_max_burst_length);
+	} else {
+		priv->dma_max_burst_length = DMA_MAX_BURST_LENGTH;
+	}
+
 	bcmgenet_set_hw_params(priv);
 
 	/* Mii wait queue */
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
index 4a8fc03d82fd..897f356eb376 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
@@ -663,6 +663,7 @@ struct bcmgenet_priv {
 	bool crc_fwd_en;
 
 	unsigned int dma_rx_chk_bit;
+	unsigned int dma_max_burst_length;
 
 	u32 msg_enable;
 
-- 
2.23.0

Re: [PATCH v1 2/3] net: bcmgenet: use optional max DMA burst size property

[Nicolas Saenz Julienne]

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Hi Matthias!
One small comment, I'll test everything later on.

On Fri, 2019-10-11 at 20:48 +0200, matthias.bgg@kernel.org wrote:
> From: Matthias Brugger <mbrugger@suse.com>
> 
> Depending on the HW, the maximal usable DMA burst size can vary.
> If not set accordingly a timeout in the transmit queue happens and no
> package can be sent. Read to optional max-burst-sz property, if not
> present, fallback to the standard value.
> 
> Signed-off-by: Matthias Brugger <mbrugger@suse.com>
> ---
> 
>  drivers/net/ethernet/broadcom/genet/bcmgenet.c | 13 +++++++++++--
>  drivers/net/ethernet/broadcom/genet/bcmgenet.h |  1 +
>  2 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> index 12cb77ef1081..a7bb822a6d83 100644
> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> @@ -2576,7 +2576,8 @@ static int bcmgenet_init_dma(struct bcmgenet_priv *priv)
>  	}
>  
>  	/* Init rDma */
> -	bcmgenet_rdma_writel(priv, DMA_MAX_BURST_LENGTH, DMA_SCB_BURST_SIZE);
> +	bcmgenet_rdma_writel(priv, priv->dma_max_burst_length,
> +			     DMA_SCB_BURST_SIZE);
>  
>  	/* Initialize Rx queues */
>  	ret = bcmgenet_init_rx_queues(priv->dev);
> @@ -2589,7 +2590,8 @@ static int bcmgenet_init_dma(struct bcmgenet_priv *priv)
>  	}
>  
>  	/* Init tDma */
> -	bcmgenet_tdma_writel(priv, DMA_MAX_BURST_LENGTH, DMA_SCB_BURST_SIZE);
> +	bcmgenet_tdma_writel(priv, priv->dma_max_burst_length,
> +			     DMA_SCB_BURST_SIZE);
>  
>  	/* Initialize Tx queues */
>  	bcmgenet_init_tx_queues(priv->dev);
> @@ -3522,6 +3524,13 @@ static int bcmgenet_probe(struct platform_device *pdev)
>  
>  	clk_prepare_enable(priv->clk);
>  
> +	if (dn) {
> +		of_property_read_u32(dn, "dma-burst-sz",
> +				     &priv->dma_max_burst_length);

You set the 'dma-burst-sz' binding as optional, though this assumes that if a
device node is available dma_max_burst_length comes from the device tree. I
think you should check of_property_read_u32's return value and on failure
default to DMA_MAX_BURST_LENGTH.

> +	} else {
> +		priv->dma_max_burst_length = DMA_MAX_BURST_LENGTH;
> +	}
> +
>  	bcmgenet_set_hw_params(priv);
>  
>  	/* Mii wait queue */
> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
> b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
> index 4a8fc03d82fd..897f356eb376 100644
> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
> @@ -663,6 +663,7 @@ struct bcmgenet_priv {
>  	bool crc_fwd_en;
>  
>  	unsigned int dma_rx_chk_bit;
> +	unsigned int dma_max_burst_length;
>  
>  	u32 msg_enable;
>  

Regards,
Nicolas


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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