From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753174AbdDRNRG (ORCPT ); Tue, 18 Apr 2017 09:17:06 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:34360 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752480AbdDRNRE (ORCPT ); Tue, 18 Apr 2017 09:17:04 -0400 Subject: Re: [PATCH v2] iTCO_wdt: all versions count down twice References: <20170405114115.17475-1-pbonzini@redhat.com> <3a2a4b95-ef9c-25d8-db48-ebf2b55e89b8@roeck-us.net> Cc: Guenter Roeck , "linux-kernel@vger.kernel.org" , andriy.shevchenko@linux.intel.com To: linux-watchdog@vger.kernel.org, wim@iguana.be From: Paolo Bonzini Message-ID: Date: Tue, 18 Apr 2017 15:17:00 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <3a2a4b95-ef9c-25d8-db48-ebf2b55e89b8@roeck-us.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/04/2017 13:46, Guenter Roeck wrote: > On 04/05/2017 04:41 AM, Paolo Bonzini 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. >> >> Cc: Wim Van Sebroeck >> Cc: Guenter Roeck >> Cc: linux-watchdog@vger.kernel.org >> Reviewed-by: Andy Shevchenko >> Signed-off-by: Paolo Bonzini > > Reviewed-by: Guenter Roeck Wim, has this been included in a tree for 4.12? The trees at linux-watchdog.git still seem empty. Thanks, Paolo >> --- >> Documentation/watchdog/watchdog-parameters.txt | 2 +- >> drivers/watchdog/iTCO_wdt.c | 22 ++++++++++------------ >> 2 files changed, 11 insertions(+), 13 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> + (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..d1d0446011c4 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" */ >> @@ -359,6 +355,8 @@ 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); >> > > -- > To unsubscribe from this list: send the line "unsubscribe > linux-watchdog" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >