[v1] watchdog: apple: Increase reset delay to 150ms

[PATCH] watchdog: apple: Increase reset delay to 150ms

Posted by Nick Chan 2 months, 2 weeks ago

The Apple A8X SoC seems to be slowest at resetting, taking up to around
125ms to reset. Wait 150ms to be safe here.

Signed-off-by: Nick Chan <towinchenmi@gmail.com>
---
 drivers/watchdog/apple_wdt.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/watchdog/apple_wdt.c b/drivers/watchdog/apple_wdt.c
index d4f739932f0b..353ecf0b04dc 100644
--- a/drivers/watchdog/apple_wdt.c
+++ b/drivers/watchdog/apple_wdt.c
@@ -127,11 +127,11 @@ static int apple_wdt_restart(struct watchdog_device *wdd, unsigned long mode,
 	/*
 	 * Flush writes and then wait for the SoC to reset. Even though the
 	 * reset is queued almost immediately experiments have shown that it
-	 * can take up to ~20-25ms until the SoC is actually reset. Just wait
-	 * 50ms here to be safe.
+	 * can take up to ~120-125ms until the SoC is actually reset. Just
+	 * wait 150ms here to be safe.
 	 */
 	(void)readl_relaxed(wdt->regs + APPLE_WDT_WD1_CUR_TIME);
-	mdelay(50);
+	mdelay(150);
 
 	return 0;
 }

base-commit: 5acd9952f95fb4b7da6d09a3be39195a80845eb6
-- 
2.46.0

Re: [PATCH] watchdog: apple: Increase reset delay to 150ms

Posted by Guenter Roeck 2 months, 2 weeks ago

On 9/13/24 10:45, Nick Chan wrote:
> The Apple A8X SoC seems to be slowest at resetting, taking up to around
> 125ms to reset. Wait 150ms to be safe here.
> 
> Signed-off-by: Nick Chan <towinchenmi@gmail.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>   drivers/watchdog/apple_wdt.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/watchdog/apple_wdt.c b/drivers/watchdog/apple_wdt.c
> index d4f739932f0b..353ecf0b04dc 100644
> --- a/drivers/watchdog/apple_wdt.c
> +++ b/drivers/watchdog/apple_wdt.c
> @@ -127,11 +127,11 @@ static int apple_wdt_restart(struct watchdog_device *wdd, unsigned long mode,
>   	/*
>   	 * Flush writes and then wait for the SoC to reset. Even though the
>   	 * reset is queued almost immediately experiments have shown that it
> -	 * can take up to ~20-25ms until the SoC is actually reset. Just wait
> -	 * 50ms here to be safe.
> +	 * can take up to ~120-125ms until the SoC is actually reset. Just
> +	 * wait 150ms here to be safe.
>   	 */
>   	(void)readl_relaxed(wdt->regs + APPLE_WDT_WD1_CUR_TIME);
> -	mdelay(50);
> +	mdelay(150);
>   
>   	return 0;
>   }
> 
> base-commit: 5acd9952f95fb4b7da6d09a3be39195a80845eb6

Re: [PATCH] watchdog: apple: Increase reset delay to 150ms

Posted by Sven Peter 2 months, 2 weeks ago

> 
> On 13. Sep 2024, at 19:46, Nick Chan <towinchenmi@gmail.com> wrote:
> 
> The Apple A8X SoC seems to be slowest at resetting, taking up to around
> 125ms to reset. Wait 150ms to be safe here.
> 
> Signed-off-by: Nick Chan <towinchenmi@gmail.com>
> ---

Reviewed-by: Sven Peter <sven@svenpeter.dev>


> drivers/watchdog/apple_wdt.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/watchdog/apple_wdt.c b/drivers/watchdog/apple_wdt.c
> index d4f739932f0b..353ecf0b04dc 100644
> --- a/drivers/watchdog/apple_wdt.c
> +++ b/drivers/watchdog/apple_wdt.c
> @@ -127,11 +127,11 @@ static int apple_wdt_restart(struct watchdog_device *wdd, unsigned long mode,
>    /*
>     * Flush writes and then wait for the SoC to reset. Even though the
>     * reset is queued almost immediately experiments have shown that it
> -     * can take up to ~20-25ms until the SoC is actually reset. Just wait
> -     * 50ms here to be safe.
> +     * can take up to ~120-125ms until the SoC is actually reset. Just
> +     * wait 150ms here to be safe.
>     */
>    (void)readl_relaxed(wdt->regs + APPLE_WDT_WD1_CUR_TIME);
> -    mdelay(50);
> +    mdelay(150);
> 
>    return 0;
> }
> 
> base-commit: 5acd9952f95fb4b7da6d09a3be39195a80845eb6
> --
> 2.46.0
>