[PATCH 8/9] watchdog: iTCO: Account for second timeout case if SMIs are not triggered

[Jan Kiszka]

From: Jan Kiszka <jan.k...@siemens.com>

Normally, the BIOS will reboot the system already on the first expiry,
when the related SMI triggered. On systems where this is disabled, e.g.
on QEMU, we will only get the reboot on the second timeout. Detect that
and adjust the timer programming accordingly.

Signed-off-by: Jan Kiszka <jan.k...@siemens.com>
---
drivers/watchdog/itco.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/watchdog/itco.c b/drivers/watchdog/itco.c
index 835e081..a1ebb06 100644
--- a/drivers/watchdog/itco.c
+++ b/drivers/watchdog/itco.c
@@ -18,6 +18,10 @@
#include <pci/header.h>
#include <sys/io.h>

+#define SMI_EN_REG 0x30
+#define TCO_EN (1 << 13)
+#define GBL_SMI_EN (1 << 0)
+
#define TCO_RLD_REG 0x00
#define TCO1_CNT_NO_REBOOT (1 << 0)
#define TCO1_CNT_REG 0x08
@@ -284,6 +288,15 @@ init(EFI_PCI_IO *pci_io, UINT16 pci_vendor_id, UINT16 pci_device_id,
Print(L"Detected Intel TCO %s watchdog\n", itco->name);

pm_base = get_pm_base(pci_io, itco);
+ if (pm_base) {
+ /*
+ * If SMIs are not triggered, the reboot will only happen on
+ * the second timeout.
+ */
+ value = inl(pm_base + SMI_EN_REG);
+ if ((value & (TCO_EN | GBL_SMI_EN)) != (TCO_EN | GBL_SMI_EN))
+ timeout /= 2;
+ }

tco_base = get_tco_base(pm_base, itco);
if (!tco_base) {
--
2.26.2