Dear Russell King - ARM Linux,

On Thu, 31 Jan 2013 15:08:01 +0000, Russell King - ARM Linux wrote:

On Thu, Jan 31, 2013 at 03:57:37PM +0100, Thomas Petazzoni wrote:

quoted

Indeed. But this function never gets called with bus->number == 0, only
with bus->number = 1, 2, 3, 4, 5, 6. So those are child busses, and
therefore they have a parent.

Having thought about it, yes, that's what I expect, because root bus
resources are never resized.  Root bus resources are normally setup
before probing to indicate what size they _can_ be and define what
space is available to the downstream devices.

Child busses (behind a PCI-2-PCI bridge) are a different matter - these
will be adjusted according to their on-bus devices and the windows for
them sized and allocated appropriately _within_ the confines of the
root bus resource.

Ok.

quoted

I am talking about the PCI-to-PCI bridges. I want the I/O windows
assigned to each PCI-to-PCI bridge to be 64K aligned. The PCI-to-PCI
bridges are devices that sit on bus 0, each giving access to the child
buses 1, 2, 3, 4, 5, 6.

Right, so you've just confirmed that this _is_ the right hook and it
_is_ being called at the right time.

Ok.

However, I had interpreted your requirement as the _host_ bridge only
(insufficient information in your previous emails, or I missed it).

Might be insufficient information, or wrong terminology on my side.

If that's what your bridge requires, then we need to detect it via
its vendor and device IDs and only apply this fixup to those bridges
which require a 64K alignment.

So, the IDs are vendor:device = 0x11ab:0x1092 ?  And let me get this
straight, it _is_ a specific requirement for this particular bridge
P2P bridge?

The vendor/device ID will change. This P2P bridge is emulated. However,
I'm not sure why you need to know the vendor:device ID to make the
fixup specific.

The fixup is already specific to those bridges, since I am just setting
pci_sys_data->win_align_io to 64K for the particular buses that are
downstream the problematic bridges. So it doesn't affect any other bus
on the system, and therefore I don't think this fixup needs to be made
specific to a given vendor:device, no?

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com