diff options
| -rw-r--r-- | drivers/acpi/acpi_watchdog.c | 59 |
1 files changed, 49 insertions, 10 deletions
diff --git a/drivers/acpi/acpi_watchdog.c b/drivers/acpi/acpi_watchdog.c index ebb626ffb5fa..4bde16fb97d8 100644 --- a/drivers/acpi/acpi_watchdog.c +++ b/drivers/acpi/acpi_watchdog.c @@ -12,23 +12,64 @@ #define pr_fmt(fmt) "ACPI: watchdog: " fmt #include <linux/acpi.h> +#include <linux/dmi.h> #include <linux/ioport.h> #include <linux/platform_device.h> #include "internal.h" +static const struct dmi_system_id acpi_watchdog_skip[] = { + { + /* + * On Lenovo Z50-70 there are two issues with the WDAT + * table. First some of the instructions use RTC SRAM + * to store persistent information. This does not work well + * with Linux RTC driver. Second, more important thing is + * that the instructions do not actually reset the system. + * + * On this particular system iTCO_wdt seems to work just + * fine so we prefer that over WDAT for now. + * + * See also https://bugzilla.kernel.org/show_bug.cgi?id=199033. + */ + .ident = "Lenovo Z50-70", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_NAME, "20354"), + DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo Z50-70"), + }, + }, + {} +}; + +static const struct acpi_table_wdat *acpi_watchdog_get_wdat(void) +{ + const struct acpi_table_wdat *wdat = NULL; + acpi_status status; + + if (acpi_disabled) + return NULL; + + if (dmi_check_system(acpi_watchdog_skip)) + return NULL; + + status = acpi_get_table(ACPI_SIG_WDAT, 0, + (struct acpi_table_header **)&wdat); + if (ACPI_FAILURE(status)) { + /* It is fine if there is no WDAT */ + return NULL; + } + + return wdat; +} + /** * Returns true if this system should prefer ACPI based watchdog instead of * the native one (which are typically the same hardware). */ bool acpi_has_watchdog(void) { - struct acpi_table_header hdr; - - if (acpi_disabled) - return false; - - return ACPI_SUCCESS(acpi_get_table_header(ACPI_SIG_WDAT, 0, &hdr)); + return !!acpi_watchdog_get_wdat(); } EXPORT_SYMBOL_GPL(acpi_has_watchdog); @@ -41,12 +82,10 @@ void __init acpi_watchdog_init(void) struct platform_device *pdev; struct resource *resources; size_t nresources = 0; - acpi_status status; int i; - status = acpi_get_table(ACPI_SIG_WDAT, 0, - (struct acpi_table_header **)&wdat); - if (ACPI_FAILURE(status)) { + wdat = acpi_watchdog_get_wdat(); + if (!wdat) { /* It is fine if there is no WDAT */ return; } |