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Sender: Guenter Roeck <groeck7@gmail.com>
Date:   Sun, 25 Sep 2022 10:38:10 -0700
From:   Guenter Roeck <linux@roeck-us.net>
To:     "Alice Guo (OSS)" <alice.guo@oss.nxp.com>
Cc:     m.felsch@pengutronix.de, wim@linux-watchdog.org,
        shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com,
        kernel@pengutronix.de, linux-imx@nxp.com,
        linux-watchdog@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 4/7] watchdog: imx7ulp_wdt: Fix RCS timeout issue
Message-ID: <20220925173810.GD1763764@roeck-us.net>
References: <20220825083256.14565-1-alice.guo@oss.nxp.com>
 <20220825083256.14565-5-alice.guo@oss.nxp.com>
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On Thu, Aug 25, 2022 at 04:32:53PM +0800, Alice Guo (OSS) wrote:
> From: Ye Li <ye.li@nxp.com>
> 
> According to measure on i.MX7ULP and i.MX8ULP, the RCS done needs
> about 3400us and 6700us respectively. So current 20us timeout is
> not enough. When reconfiguring is on-going, unlock and configure CS
> will lead to unknown result.
> 
> Increase the wait timeout value to 10ms and check the return value
> of RCS wait to fix the issue
> 
> Signed-off-by: Ye Li <ye.li@nxp.com>
> Signed-off-by: Alice Guo <alice.guo@nxp.com>
> Reviewed-by: Jacky Bai <ping.bai@nxp.com>
> Acked-by: Jason Liu <jason.hui.liu@nxp.com>

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

> ---
> 
> Changes for v2:
>  - none
> 
>  drivers/watchdog/imx7ulp_wdt.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
> index a0f6b8cea78f..12715c248688 100644
> --- a/drivers/watchdog/imx7ulp_wdt.c
> +++ b/drivers/watchdog/imx7ulp_wdt.c
> @@ -39,7 +39,7 @@
>  #define DEFAULT_TIMEOUT	60
>  #define MAX_TIMEOUT	128
>  #define WDOG_CLOCK_RATE	1000
> -#define WDOG_WAIT_TIMEOUT	20
> +#define WDOG_WAIT_TIMEOUT	10000
>  
>  static bool nowayout = WATCHDOG_NOWAYOUT;
>  module_param(nowayout, bool, 0000);
> @@ -80,7 +80,7 @@ static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable)
>  		writel(val | WDOG_CS_EN, wdt->base + WDOG_CS);
>  	else
>  		writel(val & ~WDOG_CS_EN, wdt->base + WDOG_CS);
> -	imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
> +	ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
>  
>  enable_out:
>  	local_irq_enable();
> @@ -127,7 +127,9 @@ static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog,
>  	if (ret)
>  		goto timeout_out;
>  	writel(val, wdt->base + WDOG_TOVAL);
> -	imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
> +	ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
> +	if (ret)
> +		goto timeout_out;
>  
>  	wdog->timeout = timeout;
>  
> -- 
> 2.17.1
>