[PATCH 5.14 047/172] platform/x86/intel: hid: Add DMI switches allow list

Greg Kroah-Hartman
2021-10-04T13:30:51Z

From: José Expósito <jose.exposito89@gmail.com>

commit b201cb0ebe87b209e252d85668e517ac1929e250 upstream.

Some devices, even non convertible ones, can send incorrect
SW_TABLET_MODE reports.

Add an allow list and accept such reports only from devices in it.

Bug reported for Dell XPS 17 9710 on:
https://gitlab.freedesktop.org/libinput/libinput/-/issues/662

Reported-by: Tobias Gurtzick <magic@wizardtales.com>
Suggested-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Tobias Gurtzick <magic@wizardtales.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Link: https://lore.kernel.org/r/20210920160312.9787-1-jose.exposito89@gmail.com
[hdegoede@redhat.com: Check dmi_switches_auto_add_allow_list only once]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/platform/x86/intel-hid.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)

--- a/drivers/platform/x86/intel-hid.c
+++ b/drivers/platform/x86/intel-hid.c
@@ -118,12 +118,30 @@ static const struct dmi_system_id dmi_vg
{ }
};

+/*
+ * Some devices, even non convertible ones, can send incorrect SW_TABLET_MODE
+ * reports. Accept such reports only from devices in this list.
+ */
+static const struct dmi_system_id dmi_auto_add_switch[] = {
+ {
+ .matches = {
+ DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
+ },
+ },
+ {
+ .matches = {
+ DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
+ },
+ },
+ {} /* Array terminator */
+};
+
struct intel_hid_priv {
struct input_dev *input_dev;
struct input_dev *array;
struct input_dev *switches;
bool wakeup_mode;
- bool dual_accel;
+ bool auto_add_switch;
};

#define HID_EVENT_FILTER_UUID "eeec56b3-4442-408f-a792-4edd4d758054"
@@ -452,10 +470,8 @@ static void notify_handler(acpi_handle h
* Some convertible have unreliable VGBS return which could cause incorrect
* SW_TABLET_MODE report, in these cases we enable support when receiving
* the first event instead of during driver setup.
- *
- * See dual_accel_detect.h for more info on the dual_accel check.
*/
- if (!priv->switches && !priv->dual_accel && (event == 0xcc || event == 0xcd)) {
+ if (!priv->switches && priv->auto_add_switch && (event == 0xcc || event == 0xcd)) {
dev_info(&device->dev, "switch event received, enable switches supports\n");
err = intel_hid_switches_setup(device);
if (err)
@@ -596,7 +612,8 @@ static int intel_hid_probe(struct platfo
return -ENOMEM;
dev_set_drvdata(&device->dev, priv);

- priv->dual_accel = dual_accel_detect();
+ /* See dual_accel_detect.h for more info on the dual_accel check. */
+ priv->auto_add_switch = dmi_check_system(dmi_auto_add_switch) && !dual_accel_detect();

err = intel_hid_input_setup(device);
if (err) {