diff mbox series

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

Message ID 20220816043643.26569-5-alice.guo@oss.nxp.com (mailing list archive)
State Superseded
Headers show
Series watchdog: imx7ulp_wdt: update i.MX7ULP WDOG timer driver | expand

Commit Message

Alice Guo (OSS) Aug. 16, 2022, 4:36 a.m. UTC 
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>
---
 drivers/watchdog/imx7ulp_wdt.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

Guenter Roeck Aug. 22, 2022, 2:09 p.m. UTC | #1 
On Tue, Aug 16, 2022 at 12:36:40PM +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
> 

You'll have to find a better solution. An active (non-sleep) wait of
10 ms is unacceptable.

Guenter

> 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>
> ---
>  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
>
Alice Guo (OSS) Aug. 23, 2022, 5:59 a.m. UTC | #2 
> -----Original Message-----
> From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck
> Sent: Monday, August 22, 2022 10:10 PM
> To: Alice Guo (OSS) <alice.guo@oss.nxp.com>
> Cc: wim@linux-watchdog.org; shawnguo@kernel.org;
> s.hauer@pengutronix.de; festevam@gmail.com; kernel@pengutronix.de;
> dl-linux-imx <linux-imx@nxp.com>; linux-watchdog@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; linux-kernel@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@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@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>
> > ---
> >  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
> >
Guenter Roeck Aug. 23, 2022, 12:06 p.m. UTC | #3 
On Tue, Aug 23, 2022 at 05:59:11AM +0000, Alice Guo (OSS) wrote:
> 
> 
> > -----Original Message-----
> > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck
> > Sent: Monday, August 22, 2022 10:10 PM
> > To: Alice Guo (OSS) <alice.guo@oss.nxp.com>
> > Cc: wim@linux-watchdog.org; shawnguo@kernel.org;
> > s.hauer@pengutronix.de; festevam@gmail.com; kernel@pengutronix.de;
> > dl-linux-imx <linux-imx@nxp.com>; linux-watchdog@vger.kernel.org;
> > linux-arm-kernel@lists.infradead.org; linux-kernel@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@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.
> 

That doesn't change the fact that a 10 ms hot wait is unacceptable.

Thanks,
Guenter

> Best Regards,
> Alice Guo
> 
> > > 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>
> > > ---
> > >  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
> > >
Alice Guo (OSS) Aug. 24, 2022, 6:44 a.m. UTC | #4 
> -----Original Message-----
> From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck
> Sent: Tuesday, August 23, 2022 8:07 PM
> To: Alice Guo (OSS) <alice.guo@oss.nxp.com>
> Cc: wim@linux-watchdog.org; shawnguo@kernel.org;
> s.hauer@pengutronix.de; festevam@gmail.com; kernel@pengutronix.de;
> dl-linux-imx <linux-imx@nxp.com>; linux-watchdog@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 4/7] watchdog: imx7ulp_wdt: Fix RCS timeout issue
> 
> On Tue, Aug 23, 2022 at 05:59:11AM +0000, Alice Guo (OSS) wrote:
> >
> >
> > > -----Original Message-----
> > > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck
> > > Sent: Monday, August 22, 2022 10:10 PM
> > > To: Alice Guo (OSS) <alice.guo@oss.nxp.com>
> > > Cc: wim@linux-watchdog.org; shawnguo@kernel.org;
> > > s.hauer@pengutronix.de; festevam@gmail.com; kernel@pengutronix.de;
> > > dl-linux-imx <linux-imx@nxp.com>; linux-watchdog@vger.kernel.org;
> > > linux-arm-kernel@lists.infradead.org; linux-kernel@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@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.
> >
> 
> That doesn't change the fact that a 10 ms hot wait is unacceptable.
> 
> Thanks,
> Guenter

Hi Guenter,

I plan to use readl_poll_timeout to wait for RCS(Reconfiguration Success). I think the sleep_us of readl_poll_timeout can be used to avoid a 10 ms hot wait.

Best Regards,
Alice Guo

> > Best Regards,
> > Alice Guo
> >
> > > > 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>
> > > > ---
> > > >  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
> > > >
diff mbox series

Patch

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;