3 files changed, 97 insertions, 13 deletions

diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c
index 76fb96966f7b..2f2e737be0f8 100644
--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -2123,6 +2123,25 @@ static int __init intel_opregion_present(void)
         return opregion;
 }
 
+static bool dmi_is_desktop(void)
+{
+        const char *chassis_type;
+
+        chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
+        if (!chassis_type)
+                return false;
+
+        if (!strcmp(chassis_type, "3") || /*  3: Desktop */
+            !strcmp(chassis_type, "4") || /*  4: Low Profile Desktop */
+            !strcmp(chassis_type, "5") || /*  5: Pizza Box */
+            !strcmp(chassis_type, "6") || /*  6: Mini Tower */
+            !strcmp(chassis_type, "7") || /*  7: Tower */
+            !strcmp(chassis_type, "11"))  /* 11: Main Server Chassis */
+                return true;
+
+        return false;
+}
+
 int acpi_video_register(void)
 {
         int ret = 0;
@@ -2143,8 +2162,12 @@ int acpi_video_register(void)
          * win8 ready (where we also prefer the native backlight driver, so
          * normally the acpi_video code should not register there anyways).
          */
-        if (only_lcd == -1)
-                only_lcd = acpi_osi_is_win8();
+        if (only_lcd == -1) {
+                if (dmi_is_desktop() && acpi_osi_is_win8())
+                        only_lcd = true;
+                else
+                        only_lcd = false;
+        }
 
         dmi_check_system(video_dmi_table);
 
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;
         }
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index e1eee7a60fad..f1cc4f9d31cd 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -635,4 +635,26 @@ module_param_call(lid_init_state,
                   NULL, 0644);
 MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
 
-module_acpi_driver(acpi_button_driver);
+static int acpi_button_register_driver(struct acpi_driver *driver)
+{
+        /*
+         * Modules such as nouveau.ko and i915.ko have a link time dependency
+         * on acpi_lid_open(), and would therefore not be loadable on ACPI
+         * capable kernels booted in non-ACPI mode if the return value of
+         * acpi_bus_register_driver() is returned from here with ACPI disabled
+         * when this driver is built as a module.
+         */
+        if (acpi_disabled)
+                return 0;
+
+        return acpi_bus_register_driver(driver);
+}
+
+static void acpi_button_unregister_driver(struct acpi_driver *driver)
+{
+        if (!acpi_disabled)
+                acpi_bus_unregister_driver(driver);
+}
+
+module_driver(acpi_button_driver, acpi_button_register_driver,
+               acpi_button_unregister_driver);