path: root/drivers/watchdog
diff options
authorJerry Hoemann <>2020-11-22 19:08:39 -0700
committerWim Van Sebroeck <>2020-12-13 16:17:42 +0100
commitacc195bd2cc48445ea35d00036d8c0afcc4fcc9c (patch)
treee78f29654ff3948002a3bd5ad2d4946838f97b0e /drivers/watchdog
parent42e967f3c6cb3828f07a3822d7249bccb55221a4 (diff)
watchdog/hpwdt: Disable NMI in Crash Kernel
NMIs received during the crash path are problematic as hpwdt_pretimeout handling of the NMI would cause a reentry into kdump. The situation is complicated in that I/O errors can be signaled as NMI circumventing hpwdt_pretimeout's attempt to not claim NMI not associated with either the WDT or the iLO NMI switch. These NMI can additionally cause a secondary NMI which cause the system to hang. By disabling pretimeout and hpwdtimeout in crash path we both reduce the risk of receiving an NMI and simuletaneously leave the WDT running (if it was already in use) to allow the WDT to break the system out of hangs by the WDT reset. Signed-off-by: Jerry Hoemann <> Reviewed-by: Guenter Roeck <> Link: Signed-off-by: Guenter Roeck <> Signed-off-by: Wim Van Sebroeck <>
Diffstat (limited to 'drivers/watchdog')
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
index 7d34bcf1c45b..eeb4df24a7e7 100644
--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -21,6 +21,7 @@
#include <linux/types.h>
#include <linux/watchdog.h>
#include <asm/nmi.h>
+#include <linux/crash_dump.h>
#define HPWDT_VERSION "2.0.3"
#define SECS_TO_TICKS(secs) ((secs) * 1000 / 128)
@@ -334,6 +335,11 @@ static int hpwdt_init_one(struct pci_dev *dev,
watchdog_set_nowayout(&hpwdt_dev, nowayout);
watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL);
+ if (is_kdump_kernel()) {
+ pretimeout = 0;
+ kdumptimeout = 0;
+ }
if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
pretimeout = 0;