lkml.org 
[lkml]   [2012]   [Nov]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] of: When constructing the bus id consider assigned-addresses as well
On Fri, Nov 30, 2012 at 09:48:05AM +0000, Grant Likely wrote:

> > If you attempt to stick a 'reg' in a block nested below a
> > 'device_type="pci"' the kernel throws lots of error messsages and
> > generates bad address mappings.
>
> Have you added the appropriate #address-cells and #size-cells to the pci
> device node to go back to a non-pci addressing mode?
> assigned-addresses

Switching away from the 5 dword address format is not ideal
because then there is no way to specify the resource region (prefetch,
io, mmio) and mmio would have to be assumed.

> only makes sense in the pci-device node itself. reg should work for all
> nodes below that, and if it doesn't then it is a bug that we need to
> fix.

Okay.. but how should the DTS be constructed?

pcie_bus { // The PCI-E bus
device_type = "pci";
ranges = <5dw ranges>;
#address-cells = <3>;
#size-cells = <2>;
soc_bridge { // The PCI-E device
device_type = "pci";
ranges = <5dw ranges>;

soc_device { // Internal device
assigned-address = <5dw regs>
};
};
};

This is what I have now, the soc_bridge PCI-E device is DTS modeled as
a PCI bridge - it has a ranges with its memory location, and the
children nodes are relative to those ranges. This would not be typical
for a non-bridge PCI-E device.

The reason for the 'assigned-address' requirement with the current
kernel code is the device_type=pci on soc_bridge. This makes
of_match_bus(parent) for soc_device return the PCI structure, which
has '.addresses = "assigned-addresses",'

So.. how would you like this to look?

Jason


\
 
 \ /
  Last update: 2012-12-01 02:21    [W:0.054 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site