tree c509ecea50fc60f163ed6c9e1b4ea6e5e0b9b49d
parent 6d81c0777fa6230bbec25cea0c4144345c740f2d
author Chanh Nguyen <chanh@os.amperecomputing.com> 1623405938 +0700
committer Thang Q. Nguyen <thang@os.amperecomputing.com> 1623591568 +0000

meta-ampere: Support software workaround for PSU redundancy issue

When system only uses single PSU ( ex : PSU1 ) to power ON normal 12V,
HSC2 will be trigged Fault event (FET health).
At this time, plugging in PSU2 in system, the PSU2 won't deliver power to
+12V_MB because HSC2 is protected by Fault event.
Due to HSC2 protected, the PSU redundancy mechanism can't be created.
Once PSU1 is plugged out at this moment, system will crash ( reset )
because +12V_MB dropped.
Support detecting PSU plug event and reset the Hot-Swap feature by
disabling and then enabling again it through PMBUS command to clear the
event.

Tested:
1. Plug only PSU1 to power ON system (12V)
2. Wait until host is booted, check POUT:
    $ ipmitool  sdr | grep "POUT"
    PSU1_POUT        | 112 Watts         | ok
    PSU2_POUT        | 0 Watts           | ok
3. Plug in PSU2 in system, check POUT:
   $ ipmitool sdr | grep "POUT"
   PSU1_POUT        | 64 Watts          | ok
   PSU2_POUT        | 48 Watts          | ok
4. Unplug AC power PSU1, check POUT:
   $ ipmitool sdr | grep "POUT"
   PSU1_POUT        | 0 Watts           | ok
   PSU2_POUT        | 128 Watts         | ok
5. Plug in AC power PSU1, check POUT:
   $ ipmitool sdr | grep "POUT"
   PSU1_POUT        | 80 Watts          | ok
   PSU2_POUT        | 64 Watts          | ok
6. Repeat 1. to 5. with PSU2.

Signed-off-by: Chanh Nguyen <chanh@os.amperecomputing.com>
Change-Id: Ia6e00cd7b08de48059f2450e7eaf108418d0a026