4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> commit 0d6c3011409135ea84e2a231b013a22017ff999a upstream. commit f07b3c1da92d ("HID: generic: create one input report per application type") was effectively the same as MULTI_INPUT: hidinput->report was never set, so hidinput_match_application() always returned null. Fix that by testing against the real application. Note that this breaks some old eGalax touchscreens that expect MULTI_INPUT instead of HID_QUIRK_INPUT_PER_APP. Enable this quirk for backward compatibility on all non-Win8 touchscreens. link: https://bugzilla.kernel.org/show_bug.cgi?id=200847 link: https://bugzilla.kernel.org/show_bug.cgi?id=200849 link: https://bugs.archlinux.org/task/59699 link: https://github.com/NixOS/nixpkgs/issues/45165 Cc: stable@xxxxxxxxxxxxxxx # v4.18+ Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hid/hid-input.c | 4 ++-- drivers/hid/hid-multitouch.c | 3 +++ include/linux/hid.h | 1 + 3 files changed, 6 insertions(+), 2 deletions(-) --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1579,6 +1579,7 @@ static struct hid_input *hidinput_alloca input_dev->dev.parent = &hid->dev; hidinput->input = input_dev; + hidinput->application = application; list_add_tail(&hidinput->list, &hid->inputs); INIT_LIST_HEAD(&hidinput->reports); @@ -1674,8 +1675,7 @@ static struct hid_input *hidinput_match_ struct hid_input *hidinput; list_for_each_entry(hidinput, &hid->inputs, list) { - if (hidinput->report && - hidinput->report->application == report->application) + if (hidinput->application == report->application) return hidinput; } --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -1488,6 +1488,9 @@ static int mt_probe(struct hid_device *h */ hdev->quirks |= HID_QUIRK_INPUT_PER_APP; + if (id->group != HID_GROUP_MULTITOUCH_WIN_8) + hdev->quirks |= HID_QUIRK_MULTI_INPUT; + timer_setup(&td->release_timer, mt_expired_timeout, 0); ret = hid_parse(hdev); --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -520,6 +520,7 @@ struct hid_input { const char *name; bool registered; struct list_head reports; /* the list of reports */ + unsigned int application; /* application usage for this input */ }; enum hid_type {