Dear Guenter, On Sat, 20 Sep 2014 06:51:56 -0700 Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > On 09/18/2014 11:29 PM, Jisheng Zhang wrote: > > The TOP_INIT may be zero, so the timeout period may be very short after > > initialization is done, thus the system may be reset soon after enabling. > > We fix this problem by restarting the counter immediately after enabling > > WDT. > > > > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx> > > --- > > drivers/watchdog/dw_wdt.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c > > index 9f21029..ad0619d 100644 > > --- a/drivers/watchdog/dw_wdt.c > > +++ b/drivers/watchdog/dw_wdt.c > > @@ -146,6 +146,7 @@ static int dw_wdt_open(struct inode *inode, struct > > file *filp) dw_wdt_set_top(DW_WDT_MAX_TOP); > > writel(WDOG_CONTROL_REG_WDT_EN_MASK, > > dw_wdt.regs + WDOG_CONTROL_REG_OFFSET); > > + dw_wdt_keepalive(); > > } > > > > dw_wdt_set_next_heartbeat(); > > > After getting access to the datasheet, I concluded that this fix is wrong > or at least more risky than necessary. The datasheet states that top_init, > ie bit 4-7 of the wdt_torr register, needs to be initialized with the > desired timeout period prior to enabling the watchdog. dw_wdt_set_top() > sets it to 0 instead, ie to the lowest possible timeout period. > In patch V2, I initialize the TOP_INIT when setting TOP in function dw_wdt_set_top(), this also can fix the "reboot soon" problem. Could you please have a review again? Thanks, Jisheng -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
