[PATCH 4/7] watchdog: imx7ulp_wdt: Fix RCS timeout issue

[Alice Guo (OSS)]

> -----Original Message-----
> From: Guenter Roeck <groeck7 at gmail.com> On Behalf Of Guenter Roeck
> Sent: Monday, August 22, 2022 10:10 PM
> To: Alice Guo (OSS) <alice.guo at oss.nxp.com>
> Cc: wim at linux-watchdog.org; shawnguo at kernel.org;
> s.hauer at pengutronix.de; festevam at gmail.com; kernel at pengutronix.de;
> dl-linux-imx <linux-imx at nxp.com>; linux-watchdog at vger.kernel.org;
> linux-arm-kernel at lists.infradead.org; linux-kernel at vger.kernel.org
> Subject: Re: [PATCH 4/7] watchdog: imx7ulp_wdt: Fix RCS timeout issue
> 
> On Tue, Aug 16, 2022 at 12:36:40PM +0800, Alice Guo (OSS) wrote:
> > From: Ye Li <ye.li at 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
> >
> 
> You'll have to find a better solution. An active (non-sleep) wait of
> 10 ms is unacceptable.
> 
> Guenter

Hi Guenter,

Sorry. I think this patch should be merged with " watchdog: imx7ulp_wdt: Handle wdog reconfigure failure", but I didn't merge them. I will send v2.

Best Regards,
Alice Guo

> > Signed-off-by: Ye Li <ye.li at nxp.com>
> > Signed-off-by: Alice Guo <alice.guo at nxp.com>
> > Reviewed-by: Jacky Bai <ping.bai at nxp.com>
> > Acked-by: Jason Liu <jason.hui.liu at nxp.com>
> > ---
> >  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
> >