Re: Associating nodes with phandles for pci devices

2015-03-08 16:03 GMT-07:00 Chris Packham [off-list ref]:

On 03/09/2015 11:42 AM, Arnd Bergmann wrote:

quoted

On Sunday 08 March 2015 22:01:17 Chris Packham wrote:

quoted

quoted

BTW, one thing that is high in my TODO list regarding DSA is to stop
using this platform device/driver architecture and use the actual device
driver model. Your switch driver entry point would be a pci_drive
probe's function where you end-up registering a switch the DSA. This
should solve portions of your problem although this is a long shot as we
need to convert existing drivers as well.

My current problem is that of_find_device_by_node() (called by
dsa_of_probe) can't find the device. After a bit of debugging I can see
that the populated platform bus only goes as far as
/soc/pcie-controller, anything beyond that seems to be missing. I can't
see anything obvious in of_platform_bus_create() that would actually
stop it from continuing down the pcie-controller branch provided the dts
actually enumerates the children.

Any suggestions?

The PCI devices are not populated by of_platform_bus_create. Instead,
pci_scan_device() calls pci_set_of_node() to set the of_node
pointer for each PCI device.

This would fail for instance if the root bus does not have a correct
of_node pointer.

Hmm. I instrumented pci_set_of_node and I do see my 2 network devices.

devfn = 00000000
of_node = bfff3f90 /soc/pcie-controller/pcie@1,0/tg3@01,0

devfn = 00000001
of_node = bfff4118 /soc/pcie-controller/pcie@1,0/tg3@01,1

So at least that's happening. I guess the problem is that ultimately
they are devices on the pci bus as opposed to the platform bus and
of_find_device_by_node() only looks at the platform bus

dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);

What I might have to do for now is get the DSA driver code to go looking
on the pci bus if of_find_device_by_node() fails to find the named node.

Could you try these two patches:
https://github.com/ffainelli/linux/commit/f57b2891e6118f5769c9fe17ed07e32def4c7c74
https://github.com/ffainelli/linux/commit/1ccd7b38dddd667a6ef6afe1cc3e9bb8c5599b58

Florian mentioned making the DSA code use the device driver model which
would help me but I'm kinda stuck with the kernel version I'm using for
now at least.

Right, this is still taking a bit more time than I expected, but the
two patches above remove the restriction for the network device to be
backed by a platform_device, so hopefully that can get you going. I
will CC you on the next round of patches so you can keep track of that
progress.
-- 
Florian
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