[U-Boot] ppc4xx: u-boot sees PCIe endpoint, linux does not.

[Leon Woestenberg]

Hello Stefan,

On Mon, Dec 1, 2008 at 8:46 PM, Stefan Roese <sr at denx.de> wrote:
> On Monday 01 December 2008, Leon Woestenberg wrote:
>> >> Now, if I re-program the end-point FPGA during the u-boot boot
>> >> time-out, Linux will recognize the end-point.
>> >
>> > It's possible that either the reset in between goes bonkers or something
>> > else causes your FPGA to stop responding. It looks like a programming
>> > problem with the FPGA to me.
>>
>> I have verified that the end point does not receive any kind of reset.
>>
>> Also, this problem only happens on the Canyonlands board; on x86 and
>> powerpc MPC8315E it remains properly working after soft/hard resets,
>> u-boot init etc.
>
> This could be because only the 4xx Linux PCI(e) driver really resets the
> endpoint (PHY reset). But you seem to have analyzed this already.
>

Some progress:

Using au-boot  GIT checkout of 9-2-2009 (one month old) I now have
different behaviour:
u-boot does report a link, but no longer the PCIe vendor id:

CPU:   AMCC PowerPC 460EX Rev. A at 800 MHz (PLB=200, OPB=100, EBC=100 MHz)
       Security/Kasumi support
       Bootstrap Option H - Boot ROM Location I2C (Addr 0x52)
       Internal PCI arbiter disabled
       32 kB I-Cache 32 kB D-Cache
Board: Canyonlands - AMCC PPC460EX Evaluation Board, 2*PCIe, Rev. 16
I2C:   ready
DTT:   1 is 44 C
DRAM:  512 MB (ECC not enabled, 400 MHz, CL3)
FLASH: 64 MB
NAND:  128 MiB
PCI:   Bus Dev VenId DevId Class Int
PCIE0: link is not up.
PCIE0: initialization as root-complex failed
PCIE1: successfully set as root-complex

Linux now correctly recognizes the device.
The FPGA with PCIe end point now also survives both a hard reset
(reset button) and soft reset (shutdown -r now in Linux).

Regards,
-- 
Leon