From: Jean Delvare <jdelvare@suse.de>
Date: Thu, 6 Feb 2020 16:58:45 +0100
Subject: ACPI: watchdog: Allow disabling WDAT at boot
Patch-mainline: v5.6
Git-commit: 3f9e12e0df012c4a9a7fd7eb0d3ae69b459d6b2c
References: bsc#1162557
In case the WDAT interface is broken, give the user an option to
ignore it to let a native driver bind to the watchdog device instead.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
Documentation/admin-guide/kernel-parameters.txt | 4 ++++
drivers/acpi/acpi_watchdog.c | 12 +++++++++++-
2 files changed, 15 insertions(+), 1 deletion(-)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -136,6 +136,10 @@
dynamic table installation which will install SSDT
tables to /sys/firmware/acpi/tables/dynamic.
+ acpi_no_watchdog [HW,ACPI,WDT]
+ Ignore the ACPI-based watchdog interface (WDAT) and let
+ a native driver control the watchdog device instead.
+
acpi_rsdp= [ACPI,EFI,KEXEC]
Pass the RSDP address to the kernel, mostly used
on machines running EFI runtime service to boot the
--- a/drivers/acpi/acpi_watchdog.c
+++ b/drivers/acpi/acpi_watchdog.c
@@ -58,12 +58,14 @@ static bool acpi_watchdog_uses_rtc(const
}
#endif
+static bool acpi_no_watchdog;
+
static const struct acpi_table_wdat *acpi_watchdog_get_wdat(void)
{
const struct acpi_table_wdat *wdat = NULL;
acpi_status status;
- if (acpi_disabled)
+ if (acpi_disabled || acpi_no_watchdog)
return NULL;
status = acpi_get_table(ACPI_SIG_WDAT, 0,
@@ -91,6 +93,14 @@ bool acpi_has_watchdog(void)
}
EXPORT_SYMBOL_GPL(acpi_has_watchdog);
+/* ACPI watchdog can be disabled on boot command line */
+static int __init disable_acpi_watchdog(char *str)
+{
+ acpi_no_watchdog = true;
+ return 1;
+}
+__setup("acpi_no_watchdog", disable_acpi_watchdog);
+
void __init acpi_watchdog_init(void)
{
const struct acpi_wdat_entry *entries;