Gary Thomas wrote:
Yes, I'm using the exact same kernel with these two different PCI
setups (done by the boot loader).
Restricting the memory via mem=128M has no effect - the PCI layout is
the same.
I think the outbound window size is required because of how the Linux PCI
remaps the space (note in my dumps that it put the MMIO of the boards
starting
at 0xD0000000 when the inbound window is 0x10000000)
I see where the amount of RAM is mattering -- Linux is assigning
outbound I/O space to the PCI controller itself (device 00:00.0) and the
amount that it asks for seems to differ based on memory size. Linux
ought to skip that device when assigning resources. Some platforms do
this (search for pci_exclude_device), but it seems to be missing on 83xx.
Are there any errors indicated in the device, the PCI controller, the
arbiter, etc?
None that are obvious to me.
To be clear, here are my observations:
* total memory 128MB (or less), inbound window 128MB, outbound window 128MB
==> device is happy
* total memory 256MB, inbound window 128MB, outbound window 128MB
==> device hangs, unable to access RAM (Linux handed it something
higher than 128MB)
Linux gets its idea of how much space there is to allocate from the
ranges property of the pci node in the device tree -- this should be
made to match what u-boot configures in PIWARn.
* total memory 256MB, inbound window 256MB, outbound window 128MB
==> segmentation violation when accessing device MMIO space
* total memory 256MB, inbound window 256MB, outbound window 256MB
==> access to MMIO space fails (Linux can't find device). In this
case, the SATA_SIL reports
ata1: SATA link down (SStatus FFFFFFFF SControl FFFFFFFF)
ata2: SATA link down (SStatus FFFFFFFF SControl FFFFFFFF)
which implies that the driver get's junk when accessing the device
MMIO space
Are there any other relevant messages earlier in boot, perhaps from the
PCI code failing to assign a resource?
-Scott
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