i.MX6 PCIe support

[Lucas Stach]

Hi Andrey,

Am Montag, den 30.11.2015, 10:56 -0800 schrieb Andrey Smirnov:
> Hi All,
> 
> I am working on adding EEPROM programming capabilities to e1000 driver
> on a custom i.MX6Q (automotive) board with i210 (8086:1531) connected
> over PCIe link. Unfortunately I am observing some bad/unexpected
> behavior that might indicate PCIe issues.
> 
> What I am seeing is device(i210) enumerating on PCIe bus, however any
> accesses to its registers via its memory "window" result in either
> 0xFFFFFFFF or 0xDEADBEEF. I tried accessing various PCIe configuration
> registers of that device and it seem to work fine (as a part of that
> test I read out some AER registers and they didn't indicate presence
> of any PCIe link related errors).
> 
> However when I boot Linux kernel (with 'igb' driver patched to
> recognize 8086:1531 VID:PID) on that board and run 'eepromARMtool'
> (Intel provided EEPROM programming tool) I can see it reading various
> registers correctly
> 
> My questions are:
>    - Is anyone currently using i.MX6 PCIe driver in 'next' branch?

I didn't try the latest revision, but with v2015.10.0 PCIe on i.MX6 was
working fine.

>    - Has anyone seen similar behavior on this particular controller
> and discovered the root cause?
> 
The symptoms you describe do look to me like the firmware on the i210
device doesn't get initialized. Unfortunately I don't have any specific
pointers where to start searching for the root cause.

Regards,
Lucas
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