From 3f9e12e0df012c4a9a7fd7eb0d3ae69b459d6b2c Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 6 Feb 2020 16:58:45 +0100 Subject: ACPI: watchdog: Allow disabling WDAT at boot 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 Acked-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki --- Documentation/admin-guide/kernel-parameters.txt | 4 ++++ drivers/acpi/acpi_watchdog.c | 12 +++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index dbc22d684627..c07815d230bc 100644 --- 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 diff --git a/drivers/acpi/acpi_watchdog.c b/drivers/acpi/acpi_watchdog.c index b5516b04ffc0..ab6e434b4cee 100644 --- a/drivers/acpi/acpi_watchdog.c +++ b/drivers/acpi/acpi_watchdog.c @@ -55,12 +55,14 @@ static bool acpi_watchdog_uses_rtc(const struct acpi_table_wdat *wdat) } #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, @@ -88,6 +90,14 @@ 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; -- cgit