4.19-stable review patch. If anyone has any objections, please let me know.
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From: Mika Westerberg mika.westerberg@linux.intel.com
commit ef9b7bf52c2f47f0a9bf988543c577b92c92d15e upstream.
Daniel reported that the commit 1ae3e78c0820 ("watchdog: iTCO_wdt: No need to stop the timer in probe") makes QEMU implementation of the iTCO watchdog not to trigger reboot anymore when NO_REBOOT flag is initially cleared using this option (in QEMU command line):
-global ICH9-LPC.noreboot=false
The problem with the commit is that it left the unconditional setting of NO_REBOOT that is not cleared anymore when the kernel keeps pinging the watchdog (as opposed to the previous code that called iTCO_wdt_stop() that cleared it).
Fix this so that we only set NO_REBOOT if the watchdog was not initially running.
Fixes: 1ae3e78c0820 ("watchdog: iTCO_wdt: No need to stop the timer in probe") Reported-by: Daniel P. Berrangé berrange@redhat.com Signed-off-by: Mika Westerberg mika.westerberg@linux.intel.com Tested-by: Daniel P. Berrangé berrange@redhat.com Reviewed-by: Daniel P. Berrangé berrange@redhat.com Reviewed-by: Guenter Roeck linux@roeck-us.net Link: https://lore.kernel.org/r/20221028062750.45451-1-mika.westerberg@linux.intel... Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Wim Van Sebroeck wim@linux-watchdog.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/watchdog/iTCO_wdt.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c index 930798bac582d..5ec52032117a7 100644 --- a/drivers/watchdog/iTCO_wdt.c +++ b/drivers/watchdog/iTCO_wdt.c @@ -401,14 +401,18 @@ static unsigned int iTCO_wdt_get_timeleft(struct watchdog_device *wd_dev) return time_left; }
-static void iTCO_wdt_set_running(struct iTCO_wdt_private *p) +/* Returns true if the watchdog was running */ +static bool iTCO_wdt_set_running(struct iTCO_wdt_private *p) { u16 val;
- /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is * enabled */ + /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled */ val = inw(TCO1_CNT(p)); - if (!(val & BIT(11))) + if (!(val & BIT(11))) { set_bit(WDOG_HW_RUNNING, &p->wddev.status); + return true; + } + return false; }
/* @@ -486,9 +490,6 @@ static int iTCO_wdt_probe(struct platform_device *pdev) return -ENODEV; /* Cannot reset NO_REBOOT bit */ }
- /* Set the NO_REBOOT bit to prevent later reboots, just for sure */ - p->update_no_reboot_bit(p->no_reboot_priv, true); - /* The TCO logic uses the TCO_EN bit in the SMI_EN register */ if (!devm_request_region(dev, p->smi_res->start, resource_size(p->smi_res), @@ -547,7 +548,13 @@ static int iTCO_wdt_probe(struct platform_device *pdev) watchdog_set_drvdata(&p->wddev, p); platform_set_drvdata(pdev, p);
- iTCO_wdt_set_running(p); + if (!iTCO_wdt_set_running(p)) { + /* + * If the watchdog was not running set NO_REBOOT now to + * prevent later reboots. + */ + p->update_no_reboot_bit(p->no_reboot_priv, true); + }
/* Check that the heartbeat value is within it's range; if not reset to the default */