Re: [PATCH] Input: pm8941-pwrkey - respect reboot_mode for warm reset

Hi Luca,

On Sun, Jul 11, 2021 at 11:57:25AM +0200, Luca Weiss wrote:

Hi Shawn,

On Dienstag, 29. Juni 2021 05:05:09 CEST Shawn Guo wrote:

quoted

On some devices, e.g. Sony Xperia M4 Aqua, warm reset is used to reboot
device into bootloader and recovery mode.  Instead of always doing hard
reset, add a check on reboot_mode for possible warm reset.

Signed-off-by: Shawn Guo <redacted>
---
 drivers/input/misc/pm8941-pwrkey.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/input/misc/pm8941-pwrkey.c

b/drivers/input/misc/pm8941-pwrkey.c index cf8104454e74..9b14d6eb1918
100644

--- a/drivers/input/misc/pm8941-pwrkey.c
+++ b/drivers/input/misc/pm8941-pwrkey.c

@@ -27,6 +27,7 @@
 #define PON_PS_HOLD_RST_CTL2		0x5b
 #define  PON_PS_HOLD_ENABLE		BIT(7)
 #define  PON_PS_HOLD_TYPE_MASK		0x0f
+#define  PON_PS_HOLD_TYPE_WARM_RESET	1
 #define  PON_PS_HOLD_TYPE_SHUTDOWN	4
 #define  PON_PS_HOLD_TYPE_HARD_RESET	7

@@ -93,7 +94,10 @@ static int pm8941_reboot_notify(struct notifier_block

*nb, break;
 	case SYS_RESTART:
 	default:
-		reset_type = PON_PS_HOLD_TYPE_HARD_RESET;
+		if (reboot_mode == REBOOT_WARM)

This doesn't compile with CONFIG_INPUT_PM8941_PWRKEY=m

 ERROR: modpost: "reboot_mode" [drivers/input/misc/pm8941-pwrkey.ko] undefined!

Thanks for the report!  I will add a patch to export the symbol.

Also just to clarify, this is supposed to trigger when rebooting with 
LINUX_REBOOT_CMD_RESTART2 and adding an argument that way, right?

With either of the following two methods, 'reboot_mode' will be turned
into REBOOT_WARM.

- Boot kernel with 'reboot=warm' on cmdline

- Set warm mode via sysfs entry
  $ echo warm > /sys/kernel/reboot/mode

Shawn