* [PATCH] watchdog: imx2_wdt: fix min() calculation in imx2_wdt_set_timeout
@ 2019-08-12 13:13 Rasmus Villemoes
2019-08-12 13:28 ` Guenter Roeck
0 siblings, 1 reply; 3+ messages in thread
From: Rasmus Villemoes @ 2019-08-12 13:13 UTC (permalink / raw)
To: Wim Van Sebroeck, Guenter Roeck
Cc: Georg Hofmann, linux-watchdog, linux-kernel, Rasmus Villemoes, stable
Converting from ms to s requires dividing by 1000, not multiplying. So
this is currently taking the smaller of new_timeout and 1.28e8,
i.e. effectively new_timeout.
The driver knows what it set max_hw_heartbeat_ms to, so use that
value instead of doing a division at run-time.
FWIW, this can easily be tested by booting into a busybox shell and
doing "watchdog -t 5 -T 130 /dev/watchdog" - without this patch, the
watchdog fires after 130&127 == 2 seconds.
Fixes: b07e228eee69 "watchdog: imx2_wdt: Fix set_timeout for big timeout values"
Cc: stable@vger.kernel.org # 5.2 plus anything the above got backported to
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
This should really be handled in the watchdog core for any driver that
reports max_hw_heartbeat_ms.
The same pattern appears in aspeed_wdt.c. I don't have the hardware, but
s#wdd->max_hw_heartbeat_ms * 1000#WDT_MAX_TIMEOUT_MS/1000U# should fix that one.
drivers/watchdog/imx2_wdt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 32af3974e6bb..8d019a961ccc 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -55,7 +55,7 @@
#define IMX2_WDT_WMCR 0x08 /* Misc Register */
-#define IMX2_WDT_MAX_TIME 128
+#define IMX2_WDT_MAX_TIME 128U
#define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */
#define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8)
@@ -180,7 +180,7 @@ static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
{
unsigned int actual;
- actual = min(new_timeout, wdog->max_hw_heartbeat_ms * 1000);
+ actual = min(new_timeout, IMX2_WDT_MAX_TIME);
__imx2_wdt_set_timeout(wdog, actual);
wdog->timeout = new_timeout;
return 0;
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] watchdog: imx2_wdt: fix min() calculation in imx2_wdt_set_timeout
2019-08-12 13:13 [PATCH] watchdog: imx2_wdt: fix min() calculation in imx2_wdt_set_timeout Rasmus Villemoes
@ 2019-08-12 13:28 ` Guenter Roeck
2019-08-26 12:05 ` Rasmus Villemoes
0 siblings, 1 reply; 3+ messages in thread
From: Guenter Roeck @ 2019-08-12 13:28 UTC (permalink / raw)
To: Rasmus Villemoes, Wim Van Sebroeck
Cc: Georg Hofmann, linux-watchdog, linux-kernel, stable
On 8/12/19 6:13 AM, Rasmus Villemoes wrote:
> Converting from ms to s requires dividing by 1000, not multiplying. So
> this is currently taking the smaller of new_timeout and 1.28e8,
> i.e. effectively new_timeout.
>
> The driver knows what it set max_hw_heartbeat_ms to, so use that
> value instead of doing a division at run-time.
>
> FWIW, this can easily be tested by booting into a busybox shell and
> doing "watchdog -t 5 -T 130 /dev/watchdog" - without this patch, the
> watchdog fires after 130&127 == 2 seconds.
>
> Fixes: b07e228eee69 "watchdog: imx2_wdt: Fix set_timeout for big timeout values"
> Cc: stable@vger.kernel.org # 5.2 plus anything the above got backported to
> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> ---
> This should really be handled in the watchdog core for any driver that
> reports max_hw_heartbeat_ms.
>
Good point. I'll see if I can write a patch.
Guenter
> The same pattern appears in aspeed_wdt.c. I don't have the hardware, but
> s#wdd->max_hw_heartbeat_ms * 1000#WDT_MAX_TIMEOUT_MS/1000U# should fix that one.
>
>
> drivers/watchdog/imx2_wdt.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
> index 32af3974e6bb..8d019a961ccc 100644
> --- a/drivers/watchdog/imx2_wdt.c
> +++ b/drivers/watchdog/imx2_wdt.c
> @@ -55,7 +55,7 @@
>
> #define IMX2_WDT_WMCR 0x08 /* Misc Register */
>
> -#define IMX2_WDT_MAX_TIME 128
> +#define IMX2_WDT_MAX_TIME 128U
> #define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */
>
> #define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8)
> @@ -180,7 +180,7 @@ static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
> {
> unsigned int actual;
>
> - actual = min(new_timeout, wdog->max_hw_heartbeat_ms * 1000);
> + actual = min(new_timeout, IMX2_WDT_MAX_TIME);
> __imx2_wdt_set_timeout(wdog, actual);
> wdog->timeout = new_timeout;
> return 0;
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] watchdog: imx2_wdt: fix min() calculation in imx2_wdt_set_timeout
2019-08-12 13:28 ` Guenter Roeck
@ 2019-08-26 12:05 ` Rasmus Villemoes
0 siblings, 0 replies; 3+ messages in thread
From: Rasmus Villemoes @ 2019-08-26 12:05 UTC (permalink / raw)
To: Guenter Roeck, Wim Van Sebroeck
Cc: Georg Hofmann, linux-watchdog, linux-kernel, stable
On 12/08/2019 15.28, Guenter Roeck wrote:
> On 8/12/19 6:13 AM, Rasmus Villemoes wrote:
>> Converting from ms to s requires dividing by 1000, not multiplying. So
>> this is currently taking the smaller of new_timeout and 1.28e8,
>> i.e. effectively new_timeout.
>>
>> The driver knows what it set max_hw_heartbeat_ms to, so use that
>> value instead of doing a division at run-time.
>>
>> FWIW, this can easily be tested by booting into a busybox shell and
>> doing "watchdog -t 5 -T 130 /dev/watchdog" - without this patch, the
>> watchdog fires after 130&127 == 2 seconds.
>>
>> Fixes: b07e228eee69 "watchdog: imx2_wdt: Fix set_timeout for big
>> timeout values"
>> Cc: stable@vger.kernel.org # 5.2 plus anything the above got
>> backported to
>> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
I'm not seeing this in v5.3-rc6, did it get picked up?
Rasmus
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-08-12 13:13 [PATCH] watchdog: imx2_wdt: fix min() calculation in imx2_wdt_set_timeout Rasmus Villemoes
2019-08-12 13:28 ` Guenter Roeck
2019-08-26 12:05 ` Rasmus Villemoes
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