diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index dbc22d68462751d2bb59ab35784c1c61c84bbb0a..c07815d230bcd4bde32a93c0615326f37a68824c 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 b5516b04ffc07b95a5869678f0886499fa9553bc..6e9ec6e3fe47d63ea9adf07e540ac2a223379a06 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;
@@ -126,12 +136,11 @@ void __init acpi_watchdog_init(void)
 		gas = &entries[i].register_region;
 
 		res.start = gas->address;
+		res.end = res.start + ACPI_ACCESS_BYTE_WIDTH(gas->access_width) - 1;
 		if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
 			res.flags = IORESOURCE_MEM;
-			res.end = res.start + ALIGN(gas->access_width, 4) - 1;
 		} else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
 			res.flags = IORESOURCE_IO;
-			res.end = res.start + gas->access_width - 1;
 		} else {
 			pr_warn("Unsupported address space: %u\n",
 				gas->space_id);
diff --git a/drivers/watchdog/wdat_wdt.c b/drivers/watchdog/wdat_wdt.c
index b069349b52f55f92005bd4d6429f2a1a95def739..3065dd670a18289df900c07c93f513c4d9c8f598 100644
--- a/drivers/watchdog/wdat_wdt.c
+++ b/drivers/watchdog/wdat_wdt.c
@@ -54,6 +54,13 @@ module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
+#define WDAT_DEFAULT_TIMEOUT	30
+
+static int timeout = WDAT_DEFAULT_TIMEOUT;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
+		 __MODULE_STRING(WDAT_DEFAULT_TIMEOUT) ")");
+
 static int wdat_wdt_read(struct wdat_wdt *wdat,
 	 const struct wdat_instruction *instr, u32 *value)
 {
@@ -389,7 +396,7 @@ static int wdat_wdt_probe(struct platform_device *pdev)
 
 		memset(&r, 0, sizeof(r));
 		r.start = gas->address;
-		r.end = r.start + gas->access_width - 1;
+		r.end = r.start + ACPI_ACCESS_BYTE_WIDTH(gas->access_width) - 1;
 		if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
 			r.flags = IORESOURCE_MEM;
 		} else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
@@ -438,6 +445,22 @@ static int wdat_wdt_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, wdat);
 
+	/*
+	 * Set initial timeout so that userspace has time to configure the
+	 * watchdog properly after it has opened the device. In some cases
+	 * the BIOS default is too short and causes immediate reboot.
+	 */
+	if (timeout * 1000 < wdat->wdd.min_hw_heartbeat_ms ||
+	    timeout * 1000 > wdat->wdd.max_hw_heartbeat_ms) {
+		dev_warn(dev, "Invalid timeout %d given, using %d\n",
+			 timeout, WDAT_DEFAULT_TIMEOUT);
+		timeout = WDAT_DEFAULT_TIMEOUT;
+	}
+
+	ret = wdat_wdt_set_timeout(&wdat->wdd, timeout);
+	if (ret)
+		return ret;
+
 	watchdog_set_nowayout(&wdat->wdd, nowayout);
 	return devm_watchdog_register_device(dev, &wdat->wdd);
 }
diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index a2583c2bc0548c8da7ec53f6c535c636661e8ced..4defed58ea338fd61e789751af92c5a04b04088a 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -532,11 +532,12 @@ typedef u64 acpi_integer;
 	 strnlen (a, ACPI_NAMESEG_SIZE) == ACPI_NAMESEG_SIZE)
 
 /*
- * Algorithm to obtain access bit width.
+ * Algorithm to obtain access bit or byte width.
  * Can be used with access_width of struct acpi_generic_address and access_size of
  * struct acpi_resource_generic_register.
  */
 #define ACPI_ACCESS_BIT_WIDTH(size)     (1 << ((size) + 2))
+#define ACPI_ACCESS_BYTE_WIDTH(size)    (1 << ((size) - 1))
 
 /*******************************************************************************
  *