Patch "riscv: set default pm_power_off to NULL" has been added to the 5.10-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    riscv: set default pm_power_off to NULL

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     riscv-set-default-pm_power_off-to-null.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From f2928e224d85e7cc139009ab17cefdfec2df5d11 Mon Sep 17 00:00:00 2001
From: Dimitri John Ledkov <dimitri.ledkov@xxxxxxxxxxxxx>
Date: Tue, 7 Sep 2021 01:28:47 +0100
Subject: riscv: set default pm_power_off to NULL

From: Dimitri John Ledkov <dimitri.ledkov@xxxxxxxxxxxxx>

commit f2928e224d85e7cc139009ab17cefdfec2df5d11 upstream.

Set pm_power_off to NULL like on all other architectures, check if it
is set in machine_halt() and machine_power_off() and fallback to
default_power_off if no other power driver got registered.

This brings riscv architecture inline with all other architectures,
and allows to reuse exiting power drivers unmodified.

Kernels without legacy SBI v0.1 extensions (CONFIG_RISCV_SBI_V01 is
not set), do not set pm_power_off to sbi_shutdown(). There is no
support for SBI v0.3 system reset extension either. This prevents
using gpio_poweroff on SiFive HiFive Unmatched.

Tested on SiFive HiFive unmatched, with a dtb specifying gpio-poweroff
node and kernel complied without CONFIG_RISCV_SBI_V01.

BugLink: https://bugs.launchpad.net/bugs/1942806
Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@xxxxxxxxxxxxx>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Tested-by: Ron Economos <w6rz@xxxxxxxxxxx>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/riscv/kernel/reset.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

--- a/arch/riscv/kernel/reset.c
+++ b/arch/riscv/kernel/reset.c
@@ -12,7 +12,7 @@ static void default_power_off(void)
 		wait_for_interrupt();
 }
 
-void (*pm_power_off)(void) = default_power_off;
+void (*pm_power_off)(void) = NULL;
 EXPORT_SYMBOL(pm_power_off);
 
 void machine_restart(char *cmd)
@@ -23,10 +23,16 @@ void machine_restart(char *cmd)
 
 void machine_halt(void)
 {
-	pm_power_off();
+	if (pm_power_off != NULL)
+		pm_power_off();
+	else
+		default_power_off();
 }
 
 void machine_power_off(void)
 {
-	pm_power_off();
+	if (pm_power_off != NULL)
+		pm_power_off();
+	else
+		default_power_off();
 }


Patches currently in stable-queue which might be from dimitri.ledkov@xxxxxxxxxxxxx are

queue-5.10/riscv-set-default-pm_power_off-to-null.patch