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* [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout programming is within the limits
@ 2023-02-08  8:37 George Cherian
  2023-02-08 15:10 ` Guenter Roeck
  0 siblings, 1 reply; 5+ messages in thread
From: George Cherian @ 2023-02-08  8:37 UTC (permalink / raw)
  To: wim, linux, zhangshaokun; +Cc: linux-watchdog, linux-kernel, George Cherian

Make sure to honour the max_hw_heartbeat_ms while programming the timeout
value to WOR. Clamp the timeout passed to sbsa_gwdt_set_timeout() to
make sure the programmed value is within the permissible range.

Fixes: abd3ac7902fb ("watchdog: sbsa: Support architecture version 1")

Signed-off-by: George Cherian <george.cherian@marvell.com>
---
 drivers/watchdog/sbsa_gwdt.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c
index 9791c74aebd4..ee1039a652f1 100644
--- a/drivers/watchdog/sbsa_gwdt.c
+++ b/drivers/watchdog/sbsa_gwdt.c
@@ -149,6 +149,7 @@ static int sbsa_gwdt_set_timeout(struct watchdog_device *wdd,
 {
 	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
 
+	timeout = clamp_t(unsigned int, timeout, 1, wdd->max_hw_heartbeat_ms / 1000);
 	wdd->timeout = timeout;
 
 	if (action)
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout programming is within the limits
  2023-02-08  8:37 [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout programming is within the limits George Cherian
@ 2023-02-08 15:10 ` Guenter Roeck
  2023-02-08 17:20   ` George Cherian
  0 siblings, 1 reply; 5+ messages in thread
From: Guenter Roeck @ 2023-02-08 15:10 UTC (permalink / raw)
  To: George Cherian, wim, zhangshaokun; +Cc: linux-watchdog, linux-kernel

On 2/8/23 00:37, George Cherian wrote:
> Make sure to honour the max_hw_heartbeat_ms while programming the timeout
> value to WOR. Clamp the timeout passed to sbsa_gwdt_set_timeout() to
> make sure the programmed value is within the permissible range.
> 
> Fixes: abd3ac7902fb ("watchdog: sbsa: Support architecture version 1")
> 
> Signed-off-by: George Cherian <george.cherian@marvell.com>
> ---
>   drivers/watchdog/sbsa_gwdt.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c
> index 9791c74aebd4..ee1039a652f1 100644
> --- a/drivers/watchdog/sbsa_gwdt.c
> +++ b/drivers/watchdog/sbsa_gwdt.c
> @@ -149,6 +149,7 @@ static int sbsa_gwdt_set_timeout(struct watchdog_device *wdd,
>   {
>   	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
>   
> +	timeout = clamp_t(unsigned int, timeout, 1, wdd->max_hw_heartbeat_ms / 1000);
>   	wdd->timeout = timeout;
>   

Wrong order. wdd->timeout should still contain the requested timeout.

Guenter


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout programming is within the limits
  2023-02-08 15:10 ` Guenter Roeck
@ 2023-02-08 17:20   ` George Cherian
  2023-02-08 17:55     ` Guenter Roeck
  0 siblings, 1 reply; 5+ messages in thread
From: George Cherian @ 2023-02-08 17:20 UTC (permalink / raw)
  To: Guenter Roeck, wim, zhangshaokun; +Cc: linux-watchdog, linux-kernel



> -----Original Message-----
> From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck
> Sent: Wednesday, February 8, 2023 8:41 PM
> To: George Cherian <gcherian@marvell.com>; wim@linux-watchdog.org;
> zhangshaokun@hisilicon.com
> Cc: linux-watchdog@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout
> programming is within the limits
> 
> 
> ----------------------------------------------------------------------
> On 2/8/23 00:37, George Cherian wrote:
> > Make sure to honour the max_hw_heartbeat_ms while programming the
> > timeout value to WOR. Clamp the timeout passed to
> > sbsa_gwdt_set_timeout() to make sure the programmed value is within
> the permissible range.
> >
> > Fixes: abd3ac7902fb ("watchdog: sbsa: Support architecture version 1")
> >
> > Signed-off-by: George Cherian <george.cherian@marvell.com>
> > ---
> >   drivers/watchdog/sbsa_gwdt.c | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/watchdog/sbsa_gwdt.c
> > b/drivers/watchdog/sbsa_gwdt.c index 9791c74aebd4..ee1039a652f1
> 100644
> > --- a/drivers/watchdog/sbsa_gwdt.c
> > +++ b/drivers/watchdog/sbsa_gwdt.c
> > @@ -149,6 +149,7 @@ static int sbsa_gwdt_set_timeout(struct
> watchdog_device *wdd,
> >   {
> >   	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
> >
> > +	timeout = clamp_t(unsigned int, timeout, 1, wdd-
> >max_hw_heartbeat_ms
> > +/ 1000);
> >   	wdd->timeout = timeout;
> >
> 
> Wrong order. wdd->timeout should still contain the requested timeout.
But then the requested timeout is not being set in HW.
Isn't that a disconnect?

> 
> Guenter


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout programming is within the limits
  2023-02-08 17:20   ` George Cherian
@ 2023-02-08 17:55     ` Guenter Roeck
  2023-02-09  2:09       ` George Cherian
  0 siblings, 1 reply; 5+ messages in thread
From: Guenter Roeck @ 2023-02-08 17:55 UTC (permalink / raw)
  To: George Cherian; +Cc: wim, zhangshaokun, linux-watchdog, linux-kernel

On Wed, Feb 08, 2023 at 05:20:34PM +0000, George Cherian wrote:
> 
> 
> > -----Original Message-----
> > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck
> > Sent: Wednesday, February 8, 2023 8:41 PM
> > To: George Cherian <gcherian@marvell.com>; wim@linux-watchdog.org;
> > zhangshaokun@hisilicon.com
> > Cc: linux-watchdog@vger.kernel.org; linux-kernel@vger.kernel.org
> > Subject: Re: [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout
> > programming is within the limits
> > 
> > 
> > ----------------------------------------------------------------------
> > On 2/8/23 00:37, George Cherian wrote:
> > > Make sure to honour the max_hw_heartbeat_ms while programming the
> > > timeout value to WOR. Clamp the timeout passed to
> > > sbsa_gwdt_set_timeout() to make sure the programmed value is within
> > the permissible range.
> > >
> > > Fixes: abd3ac7902fb ("watchdog: sbsa: Support architecture version 1")
> > >
> > > Signed-off-by: George Cherian <george.cherian@marvell.com>
> > > ---
> > >   drivers/watchdog/sbsa_gwdt.c | 1 +
> > >   1 file changed, 1 insertion(+)
> > >
> > > diff --git a/drivers/watchdog/sbsa_gwdt.c
> > > b/drivers/watchdog/sbsa_gwdt.c index 9791c74aebd4..ee1039a652f1
> > 100644
> > > --- a/drivers/watchdog/sbsa_gwdt.c
> > > +++ b/drivers/watchdog/sbsa_gwdt.c
> > > @@ -149,6 +149,7 @@ static int sbsa_gwdt_set_timeout(struct
> > watchdog_device *wdd,
> > >   {
> > >   	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
> > >
> > > +	timeout = clamp_t(unsigned int, timeout, 1, wdd-
> > >max_hw_heartbeat_ms
> > > +/ 1000);
> > >   	wdd->timeout = timeout;
> > >
> > 
> > Wrong order. wdd->timeout should still contain the requested timeout.
> But then the requested timeout is not being set in HW.
> Isn't that a disconnect?

No. The driver is supposed to set a timeout no larger than
max_hw_heartbeat_ms. The watchdog core then takes care of
differences between ->timeout (as seen by the user) and
max_hw_heartbeat_ms and pings the watchdog as needed.

Guenter

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout programming is within the limits
  2023-02-08 17:55     ` Guenter Roeck
@ 2023-02-09  2:09       ` George Cherian
  0 siblings, 0 replies; 5+ messages in thread
From: George Cherian @ 2023-02-09  2:09 UTC (permalink / raw)
  To: Guenter Roeck; +Cc: wim, zhangshaokun, linux-watchdog, linux-kernel



> -----Original Message-----
> From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck
> Sent: Wednesday, February 8, 2023 11:26 PM
> To: George Cherian <gcherian@marvell.com>
> Cc: wim@linux-watchdog.org; zhangshaokun@hisilicon.com; linux-
> watchdog@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout
> programming is within the limits
> 
> ----------------------------------------------------------------------
> On Wed, Feb 08, 2023 at 05:20:34PM +0000, George Cherian wrote:
> >
> >
> > > -----Original Message-----
> > > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter
> Roeck
> > > Sent: Wednesday, February 8, 2023 8:41 PM
> > > To: George Cherian <gcherian@marvell.com>; wim@linux-watchdog.org;
> > > zhangshaokun@hisilicon.com
> > > Cc: linux-watchdog@vger.kernel.org; linux-kernel@vger.kernel.org
> > > Subject: Re: [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout
> > > programming is within the limits
> > >
> > >
> > > --------------------------------------------------------------------
> > > -- On 2/8/23 00:37, George Cherian wrote:
> > > > Make sure to honour the max_hw_heartbeat_ms while programming
> the
> > > > timeout value to WOR. Clamp the timeout passed to
> > > > sbsa_gwdt_set_timeout() to make sure the programmed value is
> > > > within
> > > the permissible range.
> > > >
> > > > Fixes: abd3ac7902fb ("watchdog: sbsa: Support architecture version
> > > > 1")
> > > >
> > > > Signed-off-by: George Cherian <george.cherian@marvell.com>
> > > > ---
> > > >   drivers/watchdog/sbsa_gwdt.c | 1 +
> > > >   1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/drivers/watchdog/sbsa_gwdt.c
> > > > b/drivers/watchdog/sbsa_gwdt.c index 9791c74aebd4..ee1039a652f1
> > > 100644
> > > > --- a/drivers/watchdog/sbsa_gwdt.c
> > > > +++ b/drivers/watchdog/sbsa_gwdt.c
> > > > @@ -149,6 +149,7 @@ static int sbsa_gwdt_set_timeout(struct
> > > watchdog_device *wdd,
> > > >   {
> > > >   	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
> > > >
> > > > +	timeout = clamp_t(unsigned int, timeout, 1, wdd-
> > > >max_hw_heartbeat_ms
> > > > +/ 1000);
> > > >   	wdd->timeout = timeout;
> > > >
> > >
> > > Wrong order. wdd->timeout should still contain the requested timeout.
> > But then the requested timeout is not being set in HW.
> > Isn't that a disconnect?
> 
> No. The driver is supposed to set a timeout no larger than
> max_hw_heartbeat_ms. The watchdog core then takes care of differences
> between ->timeout (as seen by the user) and max_hw_heartbeat_ms and
> pings the watchdog as needed.
Thanks for the explanation. Will post v3.

-George
> 
> Guenter

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2023-02-09  2:10 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-08  8:37 [PATCH v2] watchdog: sbsa_wdog: Make sure the timeout programming is within the limits George Cherian
2023-02-08 15:10 ` Guenter Roeck
2023-02-08 17:20   ` George Cherian
2023-02-08 17:55     ` Guenter Roeck
2023-02-09  2:09       ` George Cherian

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