FAILED: patch "[PATCH] powerpc/pseries: Do not initiate shutdown when system is" failed to apply to 4.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 90a9b102eddf6a3f987d15f4454e26a2532c1c98 Mon Sep 17 00:00:00 2001
From: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Date: Thu, 20 Aug 2020 11:48:44 +0530
Subject: [PATCH] powerpc/pseries: Do not initiate shutdown when system is
 running on UPS

As per PAPR we have to look for both EPOW sensor value and event
modifier to identify the type of event and take appropriate action.

In LoPAPR v1.1 section 10.2.2 includes table 136 "EPOW Action Codes":

  SYSTEM_SHUTDOWN 3

  The system must be shut down. An EPOW-aware OS logs the EPOW error
  log information, then schedules the system to be shut down to begin
  after an OS defined delay internal (default is 10 minutes.)

Then in section 10.3.2.2.8 there is table 146 "Platform Event Log
Format, Version 6, EPOW Section", which includes the "EPOW Event
Modifier":

  For EPOW sensor value = 3
  0x01 = Normal system shutdown with no additional delay
  0x02 = Loss of utility power, system is running on UPS/Battery
  0x03 = Loss of system critical functions, system should be shutdown
  0x04 = Ambient temperature too high
  All other values = reserved

We have a user space tool (rtas_errd) on LPAR to monitor for
EPOW_SHUTDOWN_ON_UPS. Once it gets an event it initiates shutdown
after predefined time. It also starts monitoring for any new EPOW
events. If it receives "Power restored" event before predefined time
it will cancel the shutdown. Otherwise after predefined time it will
shutdown the system.

Commit 79872e35469b ("powerpc/pseries: All events of
EPOW_SYSTEM_SHUTDOWN must initiate shutdown") changed our handling of
the "on UPS/Battery" case, to immediately shutdown the system. This
breaks existing setups that rely on the userspace tool to delay
shutdown and let the system run on the UPS.

Fixes: 79872e35469b ("powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Massage change log and add PAPR references]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200820061844.306460-1-hegdevasant@linux.vnet.ibm.com

diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index f3736fcd98fc..13c86a292c6d 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -184,7 +184,6 @@ static void handle_system_shutdown(char event_modifier)
 	case EPOW_SHUTDOWN_ON_UPS:
 		pr_emerg("Loss of system power detected. System is running on"
 			 " UPS/battery. Check RTAS error log for details\n");
-		orderly_poweroff(true);
 		break;
 
 	case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS: