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path: root/drivers/acpi/acpi_watchdog.c
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Diffstat (limited to 'drivers/acpi/acpi_watchdog.c')
-rw-r--r--drivers/acpi/acpi_watchdog.c59
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;
}