This is a note to let you know that I've just added the patch titled HID: multitouch: require Finger field to mark Win8 reports as MT to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hid-multitouch-require-finger-field-to-mark-win8-reports-as-mt.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a2353e3b26012ff43bcdf81d37a3eaddd7ecdbf3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ahelenia=20Ziemia=C5=84ska?= <nabijaczleweli@xxxxxxxxxxxxxxxxxx> Date: Mon, 8 Mar 2021 18:42:03 +0100 Subject: HID: multitouch: require Finger field to mark Win8 reports as MT MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ahelenia Ziemiańska <nabijaczleweli@xxxxxxxxxxxxxxxxxx> commit a2353e3b26012ff43bcdf81d37a3eaddd7ecdbf3 upstream. This effectively changes collection_is_mt from contact ID in report->field to (device is Win8 => collection is finger) && contact ID in report->field Some devices erroneously report Pen for fingers, and Win8 stylus-on-touchscreen devices report contact ID, but mark the accompanying touchscreen device's collection correctly Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@xxxxxxxxxxxxxxxxxx> Acked-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hid/hid-multitouch.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -588,9 +588,13 @@ static struct mt_report_data *mt_allocat if (!(HID_MAIN_ITEM_VARIABLE & field->flags)) continue; - for (n = 0; n < field->report_count; n++) { - if (field->usage[n].hid == HID_DG_CONTACTID) - rdata->is_mt_collection = true; + if (field->logical == HID_DG_FINGER || td->hdev->group != HID_GROUP_MULTITOUCH_WIN_8) { + for (n = 0; n < field->report_count; n++) { + if (field->usage[n].hid == HID_DG_CONTACTID) { + rdata->is_mt_collection = true; + break; + } + } } } Patches currently in stable-queue which might be from nabijaczleweli@xxxxxxxxxxxxxxxxxx are queue-4.19/hid-multitouch-require-finger-field-to-mark-win8-reports-as-mt.patch