[PATCH RFC net] fsl/man: Inherit parent device and of_node

[PATCH RFC net] fsl/man: Inherit parent device and of_node

[Florian Fainelli]

Junote Cai reported that he was not able to get a DSA setup involving the
Freescale DPAA/FMAN driver to work and narrowed it down to
of_find_net_device_by_node(). This function requires the network device's
device reference to be correctly set which is the case here, though we have
lost any device_node association there.

The problem is that dpaa_eth_add_device() allocates a "dpaa-ethernet" platform
device, and later on dpaa_eth_probe() is called but SET_NETDEV_DEV() won't be
propagating &pdev->dev.of_node properly. Fix this by inherenting both the parent
device and the of_node when dpaa_eth_add_device() creates the platform device.

Fixes: 3933961682a3 ("fsl/fman: Add FMan MAC driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
Madalin,

After this patch, Junote was able to get the DSA switch probed correctly however
he was also observing a resource conflict, but I don't think this patch is responsible
for that per-se, please review:

iommu: Adding device ffe488000.port to group 21
fsl_mac ffe4e0000.ethernet: FMan dTSEC version: 0x08240101
fsl_mac ffe4e0000.ethernet: FMan MAC address: 00:04:9f:ef:05:01
fsl_mac dpaa-ethernet.0: __devm_request_mem_region(mac) failed
fsl_mac: probe of dpaa-ethernet.0 failed with error -16
fsl_mac dpaa-ethernet.0: __devm_request_mem_region(mac) failed
fsl_mac: probe of dpaa-ethernet.0 failed with error -16
fsl_dpa dpaa-ethernet.0 eth0: Probed interface eth0

 drivers/net/ethernet/freescale/fman/mac.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fman/mac.c b/drivers/net/ethernet/freescale/fman/mac.c
index 6e67d22fd0d5..1c7da16ad0ff 100644
--- a/drivers/net/ethernet/freescale/fman/mac.c
+++ b/drivers/net/ethernet/freescale/fman/mac.c
@@ -623,6 +623,8 @@ static struct platform_device *dpaa_eth_add_device(int fman_id,
 		goto no_mem;
 	}
 
+	pdev->dev.of_node = node;
+	pdev->dev.parent = priv->dev;
 	set_dma_ops(&pdev->dev, get_dma_ops(priv->dev));
 
 	ret = platform_device_add_data(pdev, &data, sizeof(data));
-- 
2.11.0

Re: [PATCH RFC net] fsl/man: Inherit parent device and of_node

[David Miller]

From: Florian Fainelli <f.fainelli@gmail.com>
Date: Fri, 18 Aug 2017 17:12:55 -0700

> @@ -623,6 +623,8 @@ static struct platform_device *dpaa_eth_add_device(int fman_id,
>  		goto no_mem;
>  	}
>  
> +	pdev->dev.of_node = node;
> +	pdev->dev.parent = priv->dev;
>  	set_dma_ops(&pdev->dev, get_dma_ops(priv->dev));
>  
>  	ret = platform_device_add_data(pdev, &data, sizeof(data));

I guess since we allocate and manage the platform device here, we can
fumble around safely with it's device node pointer and parent.

So this should be ok.