On Wed, Apr 5, 2017 at 12:03 PM, Paolo Bonzini <[email protected]> wrote: > The ICH9 is listed as having TCO v2, and indeed the behavior in the > datasheet corresponds to v2 (for example the NO_REBOOT flag is > accessible via the 16KiB-aligned Root Complex Base Address). > > However, the TCO counts twice just like in v1; the documentation > of the SECOND_TO_STS bit says: "ICH9 sets this bit to 1 to indicate > that the TIMEOUT bit had been (or is currently) set and a second > timeout occurred before the TCO_RLD register was written. If this > bit is set and the NO_REBOOT config bit is 0, then the ICH9 will > reboot the system after the second timeout. The same can be found > in the BayTrail (Atom E3800) datasheet, and even HOWTOs around > the Internet say that it will reboot after _twice_ the specified > heartbeat. > > I did not find the Apollo Lake datasheet, but because v4/v5 has > a SECOND_TO_STS bit just like the previous version I'm enabling > this for Apollo Lake as well.
Regarding to last proposed changes Apollo Lake has some register offset issue. Nevertheless, this patch AFAIU still applies. One nit below. Reviewed-by: Andy Shevchenko <[email protected]> > > Cc: Wim Van Sebroeck <[email protected]> > Cc: Guenter Roeck <[email protected]> > Cc: [email protected] > Signed-off-by: Paolo Bonzini <[email protected]> > --- > Documentation/watchdog/watchdog-parameters.txt | 2 +- > drivers/watchdog/iTCO_wdt.c | 23 ++++++++++------------- > 2 files changed, 11 insertions(+), 14 deletions(-) > > diff --git a/Documentation/watchdog/watchdog-parameters.txt > b/Documentation/watchdog/watchdog-parameters.txt > index 4f7d86dd0a5d..914518aeb972 100644 > --- a/Documentation/watchdog/watchdog-parameters.txt > +++ b/Documentation/watchdog/watchdog-parameters.txt > @@ -117,7 +117,7 @@ nowayout: Watchdog cannot be stopped once started > ------------------------------------------------- > iTCO_wdt: > heartbeat: Watchdog heartbeat in seconds. > - (2<heartbeat<39 (TCO v1) or 613 (TCO v2), default=30) > + (5<=heartbeat<=74 (TCO v1) or 1226 (TCO v2), default=30) > nowayout: Watchdog cannot be stopped once started > (default=kernel config parameter) > ------------------------------------------------- > diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c > index 3d0abc0d59b4..c9230a0cdc83 100644 > --- a/drivers/watchdog/iTCO_wdt.c > +++ b/drivers/watchdog/iTCO_wdt.c > @@ -280,16 +280,15 @@ static int iTCO_wdt_ping(struct watchdog_device *wd_dev) > > iTCO_vendor_pre_keepalive(p->smi_res, wd_dev->timeout); > > + /* Reset the timeout status bit so that the timer > + * needs to count down twice again before rebooting */ > + outw(0x0008, TCO1_STS(p)); /* write 1 to clear bit */ > + > /* Reload the timer by writing to the TCO Timer Counter register */ > - if (p->iTCO_version >= 2) { > + if (p->iTCO_version >= 2) > outw(0x01, TCO_RLD(p)); > - } else if (p->iTCO_version == 1) { > - /* Reset the timeout status bit so that the timer > - * needs to count down twice again before rebooting */ > - outw(0x0008, TCO1_STS(p)); /* write 1 to clear bit */ > - > + else if (p->iTCO_version == 1) > outb(0x01, TCO_RLD(p)); > - } > > spin_unlock(&p->io_lock); > return 0; > @@ -302,11 +301,8 @@ static int iTCO_wdt_set_timeout(struct watchdog_device > *wd_dev, unsigned int t) > unsigned char val8; > unsigned int tmrval; > > - tmrval = seconds_to_ticks(p, t); > - > - /* For TCO v1 the timer counts down twice before rebooting */ > - if (p->iTCO_version == 1) > - tmrval /= 2; > + /* The timer counts down twice before rebooting */ > + tmrval = seconds_to_ticks(p, t) / 2; > > /* from the specs: */ > /* "Values of 0h-3h are ignored and should not be attempted" */ > @@ -359,8 +355,9 @@ static unsigned int iTCO_wdt_get_timeleft(struct > watchdog_device *wd_dev) > spin_lock(&p->io_lock); > val16 = inw(TCO_RLD(p)); > val16 &= 0x3ff; > + if (!(inw(TCO1_STS(p)) & 0x0008)) > + val16 += (inw(TCOv2_TMR(p)) & 0x3ff); > spin_unlock(&p->io_lock); > - > time_left = ticks_to_seconds(p, val16); This change does not belong to the patch. > } else if (p->iTCO_version == 1) { > spin_lock(&p->io_lock); > -- > 2.9.3 > -- With Best Regards, Andy Shevchenko
