tree c6daba11cb52c34291f6463d1e213b697a463191
parent 1e04d94b226ddc9de7384706ecc500a208867bd6
author Timothy Chen <timothytim@google.com> 1651689922 -0700
committer tjaychen <timothytim@google.com> 1651769811 -0700

[flash_ctrl] Select appropriate ready's based on request source

- fixes #12381
- the previous design used the read stage's ready for arbitration.
  Due to the way the design is currently done, the read stage ready
  is actually dependent on the the downstream flash macro actually
  ack-ing the transaction.  To fix this, we would need to de-couple
  the req/ack interface on the side facing the phy and the side facing
  the macro.  While this is doable, it would also require us to latch
  incoming bus attributes.  However, there is not a lot to gain by doing
  so, because as long as the flash has not responded, the next read
  cannot proceed anyways.
- This dependency can cause program/erase operations to lock-up if the
  the downstream macro does not always keep ack asserted when idle (in
  effect behaving more like ready).
- Even though the above fix would be cleaner long term, the quick fix is
  simply to pick the appropriate ready for host and controller operations
  separately.

Signed-off-by: Timothy Chen <timothytim@google.com>