Re: [PATCH] of: When constructing the bus id considerassigned-addresses as well

From: Jason Gunthorpe
Date: Mon Nov 26 2012 - 13:20:48 EST


On Mon, Nov 26, 2012 at 02:03:16PM +0000, Grant Likely wrote:
> On Wed, 21 Nov 2012 14:02:40 -0700, Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx> wrote:
> > 'assigned-addresses' is used for certain PCI device type nodes in
> > lieu of 'reg', since this is enforced by of/address.c, have
> > of_device_make_bus_id look there as well.
> >
> > Signed-off-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
>
> If it is a PCI device, then of_device_make_bus_id() shouldn't come into
> play. PCI devices already have their own naming scheme. Only
> platform_bus device creation uses of_device_make_bus_id(). What am I
> missing?

In my embedded case I have a complex PCI-E connected SOC device.

This is modeled in OF by having a PCI-E bus, a PCI-E device node, and
then all of the SOC devices (I2C, GPIO, drivers, etc) placed under the
PCI-E device node.

The PCI driver that matches the device just turns it on and calls
of_platform_populate(..) with its own node as an argument.

So of_device_make_bus_id isn't called on a PCI-E device node, it is
called on the platform_device children of that node, and due to the
way the other code works, and what the OF rules seem to be, those
childen all use assigned-addresses. Without this patch the code just
assigns monotonic ids to those nodes.

Jason
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