[PATCH v2] Input: i8042 - disable KBD port on Razer Blade Stealth V2 (2017 model)

[Lyude Paul]

The late 2017 model of the Razer Blade Stealth has a built-in USB
keyboard, but for some reason the BIOS exposes an i8042 controller with
a connected KBD port. While this fake AT Keyboard device doesn't appear
to report any events, attempting to change the state of the caps lock
LED on it from on to off causes the entire system to hang.

So, introduce a quirk table for disabling keyboard probing by default,
i8042_dmi_nokbd_table, and add this specific model of Razer laptop to
that table.

Changes since v1:
- Correct model (should be V2, 2017)

Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
 drivers/input/serio/i8042-x86ia64io.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h
index 136f6e7bf797..f65570691980 100644
--- a/drivers/input/serio/i8042-x86ia64io.h
+++ b/drivers/input/serio/i8042-x86ia64io.h
@@ -884,6 +884,22 @@ static const struct dmi_system_id __initconst i8042_dmi_kbdreset_table[] = {
 	{ }
 };
 
+static const struct dmi_system_id i8042_dmi_nokbd_table[] __initconst = {
+	{
+		/*
+		 * Razer Blade Stealth V2 (2017 model) - Keyboard is on USB
+		 * but the system exposes a fake AT keyboard that crashes the
+		 * system if the caps lock LED is changed
+		 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Razer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Blade Stealth"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "2.04"),
+		},
+	},
+	{ }
+};
+
 #endif /* CONFIG_X86 */
 
 #ifdef CONFIG_PNP
@@ -1040,6 +1056,9 @@ static int __init i8042_pnp_init(void)
 #ifdef CONFIG_X86
 	if (dmi_check_system(i8042_dmi_nopnp_table))
 		i8042_nopnp = true;
+
+	if (dmi_check_system(i8042_dmi_nokbd_table))
+		i8042_nokbd = true;
 #endif
 
 	if (i8042_nopnp) {
-- 
2.20.1