On 4/21/21 8:46 PM, 王擎 wrote:
>
>> On 4/21/21 7:45 PM, Wang Qing wrote:
>>> Use the bark interrupt as the pretimeout notifier if available.
>>>
>>> When the watchdog timer expires in dual mode, an interrupt will be
>>> triggered first, then the timing restarts. The reset signal will be
>>> initiated when the timer expires again.
>>>
>>> The pretimeout notification shall occur at timeout-sec/2.
>>>
>>> V2:
>>> - panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled.
>>>
>>> V3:
>>> - Modify the pretimeout behavior, manually reset after the pretimeout
>>> - is processed and wait until timeout.
>>>
>>> V4:
>>> - Remove pretimeout related processing.
>>> - Add dual mode control separately.
>>>
>>> V5:
>>> - Fix some formatting and printing problems.
>>>
>>> V6:
>>> - Realize pretimeout processing through dualmode.
>>>
>>> Signed-off-by: Wang Qing <wangqing@xxxxxxxx>
>>> ---
>>> drivers/watchdog/mtk_wdt.c | 53 +++++++++++++++++++++++++++++++++++++++++-----
>>> 1 file changed, 48 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
>>> index 97ca993..ebc648b
>>> --- a/drivers/watchdog/mtk_wdt.c
>>> +++ b/drivers/watchdog/mtk_wdt.c
>>> @@ -25,6 +25,7 @@
>>> #include <linux/reset-controller.h>
>>> #include <linux/types.h>
>>> #include <linux/watchdog.h>
>>> +#include <linux/interrupt.h>
>>>
>>> #define WDT_MAX_TIMEOUT 31
>>> #define WDT_MIN_TIMEOUT 1
>>> @@ -184,15 +185,22 @@ static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
>>> {
>>> struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
>>> void __iomem *wdt_base = mtk_wdt->wdt_base;
>>> + unsigned int timeout_interval;
>>> u32 reg;
>>>
>>> - wdt_dev->timeout = timeout;
>>> + timeout_interval = wdt_dev->timeout = timeout;
>>> + /*
>>> + * In dual mode, irq will be triggered at timeout/2
>>> + * the real timeout occurs at timeout
>>> + */
>>> + if (wdt_dev->pretimeout)
>>> + timeout_interval = wdt_dev->pretimeout = timeout/2;
>>
>> Please run checkpatch --strict and fix what it reports.
>> Also, there should be a set_pretimeout function to set the
>> pretimeout. It is ok to update it here, but it should be set
>> in its own function to make sure that the actual value
>> is reported back to userspace.
>>
>> Thanks,
>> Guenter
>
> The reason why the set_pretimeout interface is not provided is
> because the pretimeout is fixed after the timeout is set, we need
> to modify timeout after setting pretimeout, which is puzzling.
>
What you need to do is to set pretimeout = timeout / 2 if a pretimeout
is set to a value != 0. Just like we adjust timeout to valid values
when set, we adjust pretimeout as well. I don't see a problem with that.
Guenter
