linux-imx

IB/hfi1: Ignore LNI errors before DC8051 transitions to Polling state

When it is requested to change its physical state back to Offline while in
the process to go up, DC8051 will set the ERROR field in the
DC8051_DBG_ERR_INFO_SET_BY_8051 register. This ERROR field will remain
until the next time when DC8051 transitions from Offline to Polling.
Subsequently, when the host requests DC8051 to change its physical state
to Polling again, it may receive a DC8051 interrupt with the stale ERROR
field still in DC8051_DBG_ERR_INFO_SET_BY_8051. If the host link state has
been changed to Polling, this stale ERROR will force the host to
transition to Offline state, resulting in a vicious cycle of Polling
->Offline->Polling->Offline. On the other hand, if the host link state is
still Offline when the stale ERROR is received, the stale ERROR will be
ignored, and the link will come up correctly.  This patch implements the
correct behavior by changing host link state to Polling only after DC8051
changes its physical state to Polling.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Krzysztof Goreczny <krzysztof.goreczny@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>