evdev: filter unreliable tablet mode switch events

If we know that the tablet mode switch is bogus anyway, filter the event and
don't pass it to the caller. They won't know whether it's bogus so the only
result we get here is buggy behaviour.

This is the simplest solution here, it filters the mode switch at the lowest
level and thus the caller won't know that the tablet even has a mode switch at
all. Where the device doesn't have any other switches it'll also lose the
switch capability.

This may cause issues in some niche cases where the event node only has
that one bit and we now disabled it leaving us with a zero-event bit device.
Shouldn't matter to callers, but let's see.

Fixes #491

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

diff --git a/meson.build b/meson.build
index 27581b81b9b4a69d3a65d4272b66c97b1ba5077a..170b7f729618d49d3fcc377d679ede657b3dbcea 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -842,6 +842,7 @@ if get_option('tests')
                'test/litest-device-synaptics-st.c',
                'test/litest-device-synaptics-t440.c',
                'test/litest-device-synaptics-x1-carbon-3rd.c',
+               'test/litest-device-tablet-mode-switch.c',
                'test/litest-device-thinkpad-extrabuttons.c',
                'test/litest-device-trackpoint.c',
                'test/litest-device-touch-screen.c',

diff --git a/src/evdev.c b/src/evdev.c
index dae1284dd529728eee38062ee985be1c67edfcea..124b07a012cd82e1e37d33f5fbbd1626875af803 100644 (file)
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -1923,15 +1923,20 @@ evdev_configure_device(struct evdev_device *device)
 
                if (libevdev_has_event_code(evdev, EV_SW, SW_TABLET_MODE)) {
                    if (evdev_device_has_model_quirk(device,
-                                QUIRK_MODEL_TABLET_MODE_SWITCH_UNRELIABLE))
+                                QUIRK_MODEL_TABLET_MODE_SWITCH_UNRELIABLE)) {
                            evdev_log_info(device,
-                               "device is an unreliable tablet mode switch.\n");
-                   else
+                               "device is an unreliable tablet mode switch, filtering events.\n");
+                           libevdev_disable_event_code(device->evdev,
+                                                       EV_SW,
+                                                       SW_TABLET_MODE);
+                   } else {
                            device->tags |= EVDEV_TAG_TABLET_MODE_SWITCH;
+                           device->seat_caps |= EVDEV_DEVICE_SWITCH;
+                   }
+               }
 
-                   device->seat_caps |= EVDEV_DEVICE_SWITCH;
+               if (device->seat_caps & EVDEV_DEVICE_SWITCH)
                    evdev_log_info(device, "device is a switch device\n");
-               }
        }
 
        if (device->seat_caps & EVDEV_DEVICE_POINTER &&

diff --git a/test/litest-device-tablet-mode-switch.c b/test/litest-device-tablet-mode-switch.c
new file mode 100644 (file)
index 0000000..e677ddf
--- /dev/null
+++ b/test/litest-device-tablet-mode-switch.c
@@ -0,0 +1,66 @@
+/*
+ * Copyright © 2020 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "config.h"
+
+#include "litest.h"
+#include "litest-int.h"
+
+static struct input_id input_id = {
+       .bustype = 0x18,
+       .vendor = 0x123,
+       .product = 0x456,
+};
+
+static int events[] = {
+       /* buttons are needed - the unreliable quirk removes SW_TABLET_MODE
+        * so we'd end up with a device with no seat caps and that won't get
+        * added */
+       EV_KEY, BTN_LEFT,
+       EV_KEY, BTN_RIGHT,
+       EV_SW, SW_TABLET_MODE,
+       -1, -1,
+};
+
+static const char quirk_file[] =
+"[litest unreliable tablet mode switch]\n"
+"MatchName=litest Unreliable Tablet Mode Switch device\n"
+"ModelTabletModeSwitchUnreliable=1\n";
+
+TEST_DEVICE("tablet-mode-switch-unreliable",
+       .type = LITEST_TABLET_MODE_UNRELIABLE,
+       .features = LITEST_SWITCH,
+       .interface = NULL,
+
+       .name = "Unreliable Tablet Mode Switch device",
+       .id = &input_id,
+       .events = events,
+       .absinfo = NULL,
+
+       .quirk_file = quirk_file,
+       .udev_properties = {
+               { "ID_INPUT_SWITCH", "1" },
+               { NULL },
+       }
+)
+

diff --git a/test/litest.h b/test/litest.h
index ff28a599172891ad6fbb9a4c49d6fa24b9740d41..c32e58acc52b15c89b07adc597c3d6f85090a93c 100644 (file)
--- a/test/litest.h
+++ b/test/litest.h
@@ -303,6 +303,7 @@ enum litest_device_type {
        LITEST_ALPS_3FG,
        LITEST_ELAN_TABLET,
        LITEST_ABSINFO_OVERRIDE,
+       LITEST_TABLET_MODE_UNRELIABLE,
 };
 
 #define LITEST_DEVICELESS      -2

diff --git a/test/test-switch.c b/test/test-switch.c
index 16838a86fd20b19b8fff08da8d08a9973499aef6..339519ebc87dce9f88b3dff316184c20b4238718 100644 (file)
--- a/test/test-switch.c
+++ b/test/test-switch.c
@@ -47,6 +47,14 @@ START_TEST(switch_has_cap)
 {
        struct litest_device *dev = litest_current_device();
 
+       /* Need to check for this specific device here because the
+        * unreliable tablet mode switch removes the capability too */
+       if (dev->which == LITEST_TABLET_MODE_UNRELIABLE) {
+               ck_assert(!libinput_device_has_capability(dev->libinput_device,
+                                                         LIBINPUT_DEVICE_CAP_SWITCH));
+               return;
+       }
+
        ck_assert(libinput_device_has_capability(dev->libinput_device,
                                                 LIBINPUT_DEVICE_CAP_SWITCH));
 
@@ -66,16 +74,33 @@ START_TEST(switch_has_lid_switch)
 }
 END_TEST
 
+static bool
+tablet_mode_switch_is_reliable(struct litest_device *dev)
+{
+       bool is_unreliable = false;
+
+       quirks_get_bool(dev->quirks,
+               QUIRK_MODEL_TABLET_MODE_SWITCH_UNRELIABLE,
+               &is_unreliable);
+
+       return !is_unreliable;
+}
+
 START_TEST(switch_has_tablet_mode_switch)
 {
        struct litest_device *dev = litest_current_device();
+       int has_switch;
 
        if (!libevdev_has_event_code(dev->evdev, EV_SW, SW_TABLET_MODE))
                return;
 
-       ck_assert_int_eq(libinput_device_switch_has_switch(dev->libinput_device,
-                                                          LIBINPUT_SWITCH_TABLET_MODE),
-                        1);
+       has_switch = libinput_device_switch_has_switch(dev->libinput_device,
+                                                      LIBINPUT_SWITCH_TABLET_MODE);
+
+       if (!tablet_mode_switch_is_reliable(dev))
+               ck_assert_int_ne(has_switch, 1);
+       else
+               ck_assert_int_eq(has_switch, 1);
 }
 END_TEST