[Skiboot] [PATCH V2] Retry link training at PCIe GEN1 if presence detected but

[Stewart Smith]

Timothy Pearson <tpearson at raptorengineering.com> writes:
>  training repeatedly failed
>
> Certain older PCIe 1.0 devices will not train unless the training process starts at GEN1 speeds.
> As a last resort when a device will not train, fall back to GEN1 speed for the last training attempt.
>
> This is verified to fix devices based on the Conexant CX23888 on the Talos II platform.
>
> Signed-off-by: Timothy Pearson <tpearson at raptorengineering.com>
> ---
>  hw/phb4.c      | 63 ++++++++++++++++++++++++++++++++++++++------------
>  include/phb4.h |  2 +-
>  2 files changed, 49 insertions(+), 16 deletions(-)

Sorry for the delay in looking at this. I fixed up a couple of minor
things when merging, including a trivial merge conflict and the missing
dt_max_link_speed member of struct phb4.

I've created a issue for op-test to attempt to add/augment the tests we
have there to test this
https://github.com/open-power/op-test-framework/issues/430 but haven't
thought in depth how we may attack it.

Anyway, merged to master as of 8b26e29acbc84e8bd5e18af194efd693b8b70912

-- 
Stewart Smith
OPAL Architect, IBM.