[PATCH 0/2] arm64: small updates to rebooting

[PATCH 0/2] arm64: small updates to rebooting

[Wolfram Sang]

Found these while working with a new prototype board.

Wolfram Sang (2):
  arm64: add grace period when rebooting
  arm64: proper comment formatting in reboot handler

 arch/arm64/kernel/process.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

-- 
2.29.2

[PATCH 1/2] arm64: add grace period when rebooting

[Wolfram Sang]

I work on a system where I currently need to reboot via watchdog.
Because the watchdog needs a bit of time to fire, add a grace period
like on arm32 to avoid the false positive warning message.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 arch/arm64/kernel/process.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 6616486a58fe..3c770329364f 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -204,6 +204,9 @@ void machine_restart(char *cmd)
 	else
 		do_kernel_restart(cmd);
 
+	/* Give a grace period for failure to restart of 1s */
+	mdelay(1000);
+
 	/*
 	 * Whoops - the architecture was unable to reboot.
 	 */
-- 
2.29.2

[PATCH 2/2] arm64: proper comment formatting in reboot handler

[Wolfram Sang]

This comment was probably copied from arm32 and then shortened. It fits
to single line now.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 arch/arm64/kernel/process.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 3c770329364f..e68dacbc6204 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -207,9 +207,7 @@ void machine_restart(char *cmd)
 	/* Give a grace period for failure to restart of 1s */
 	mdelay(1000);
 
-	/*
-	 * Whoops - the architecture was unable to reboot.
-	 */
+	/* Whoops - the architecture was unable to reboot */
 	printk("Reboot failed -- System halted\n");
 	while (1);
 }
-- 
2.29.2

Re: [PATCH 2/2] arm64: proper comment formatting in reboot handler

[Geert Uytterhoeven]

On Sat, Dec 19, 2020 at 3:38 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> This comment was probably copied from arm32 and then shortened. It fits
> to single line now.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/2] arm64: add grace period when rebooting

[Will Deacon]

On Sat, Dec 19, 2020 at 03:36:46PM +0100, Wolfram Sang wrote:
> I work on a system where I currently need to reboot via watchdog.
> Because the watchdog needs a bit of time to fire, add a grace period
> like on arm32 to avoid the false positive warning message.

Please can you elaborate a bit on the control flow here, specifically
from the part which arms the watchdog to how we end up in at the mdelay()?

Ideally, the mdelay() would live in some code that knows about the watchdog,
and therefore can choose the appropriate delay.

Thanks,

Will

Re: [PATCH 1/2] arm64: add grace period when rebooting

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 215 bytes --]

Hi Will,

> Ideally, the mdelay() would live in some code that knows about the watchdog,
> and therefore can choose the appropriate delay.

Agreed. I'll put the delay into the watchdog driver.

Thanks,

   Wolfram


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]