[PATCH] platform/x86: peaq-wmi: Add DMI check before binding to the WMI interface

[Hans de Goede <hdegoede@redhat.com>]

It seems that the WMI GUID used by the PEAQ 2-in-1 WMI hotkeys is not
as unique as a GUID should be and is used on some other devices too.

This is causing spurious key-press reports on these other devices.

This commits adds a DMI check to the PEAQ 2-in-1 WMI hotkeys driver to
ensure that it is actually running on a PEAQ 2-in-1, fixing the
spurious key-presses on these other devices.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1497861
BugLink: https://bugzilla.suse.com/attachment.cgi?id=743182
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/platform/x86/peaq-wmi.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/platform/x86/peaq-wmi.c b/drivers/platform/x86/peaq-wmi.c
index bc98ef95514a..67fa3fa32011 100644
--- a/drivers/platform/x86/peaq-wmi.c
+++ b/drivers/platform/x86/peaq-wmi.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/dmi.h>
 #include <linux/input-polldev.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -64,8 +65,22 @@ static void peaq_wmi_poll(struct input_polled_dev *dev)
 	}
 }
 
+/* Some other devices (Shuttle XS35) use the same WMI GUID for other purposes */
+static const struct dmi_system_id peaq_dmi_table[] = {
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "PEAQ"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "PEAQ PMM C1010 MD99187"),
+		},
+	},
+};
+
 static int __init peaq_wmi_init(void)
 {
+	/* WMI GUID is not unique, also check for a DMI match */
+	if (!dmi_check_system(peaq_dmi_table))
+		return -ENODEV;
+
 	if (!wmi_has_guid(PEAQ_DOLBY_BUTTON_GUID))
 		return -ENODEV;
 
@@ -86,6 +101,9 @@ static int __init peaq_wmi_init(void)
 
 static void __exit peaq_wmi_exit(void)
 {
+	if (!dmi_check_system(peaq_dmi_table))
+		return;
+
 	if (!wmi_has_guid(PEAQ_DOLBY_BUTTON_GUID))
 		return;
 
-- 
2.14.2