From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 17495265CDD; Tue, 21 Oct 2025 20:08:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761077282; cv=none; b=Ei7B0eYIst3wXAxHlmuekaJWxaIqsNPEWK3Th6IPBTAGZ5gB+LsgFUmZ0ZrZ/xbRXXpvY83apoQDaTRgIvNLGPcvezj46eLtLpiej9tqYo40Naf9GtOs94LH0+rCPq9ZugcTJo3phRgCFtHKu+a3JyaxFvq9jfPzI93fBtk/b50= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761077282; c=relaxed/simple; bh=aSsbQLatBIKL3r2Bog28U9wn9AR9lMfbYKCKTfKWIyc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DAGcPYgjJTT47LUvHNhrUgxYGMR+fT4KoQ5sQvtyxE4tnQDWx0FJ/GVV4+v0YK1VFk5OuYf/psufX1V2OrzwvZ2305kQ718nLDkSj/Sy++DXoZ1oK3Me1q3D6kIX2OudUitfebnQUDTOVVMR4DemeNXgoGYpMf1H3vTXD+AApjE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=r3ESUHSq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="r3ESUHSq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AB28C4CEF1; Tue, 21 Oct 2025 20:08:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761077282; bh=aSsbQLatBIKL3r2Bog28U9wn9AR9lMfbYKCKTfKWIyc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r3ESUHSqQJlbfLaivK9O9nnhXgUDmfcSJRFihsBAW0uDShtbz4pT2SaX3Vycrr+3X tBh5cYODpqCNt82stwg3w6GdK58eUIog3LIL1u6GE7QdKxkO9nW76rkR7UXz0lneRZ lqv68CUG8Do0l2BKyHwLGlurg+qOnm6yWfTl+7NE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Benjamin Tissoires , Jiri Kosina Subject: [PATCH 6.17 057/159] HID: multitouch: fix sticky fingers Date: Tue, 21 Oct 2025 21:50:34 +0200 Message-ID: <20251021195044.587404982@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251021195043.182511864@linuxfoundation.org> References: <20251021195043.182511864@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Tissoires commit 46f781e0d151844589dc2125c8cce3300546f92a upstream. The sticky fingers quirk (MT_QUIRK_STICKY_FINGERS) was only considering the case when slots were not released during the last report. This can be problematic if the firmware forgets to release a finger while others are still present. This was observed on the Synaptics DLL0945 touchpad found on the Dell XPS 9310 and the Dell Inspiron 5406. Fixes: 4f4001bc76fd ("HID: multitouch: fix rare Win 8 cases when the touch up event gets missing") Cc: stable@vger.kernel.org Signed-off-by: Benjamin Tissoires Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-multitouch.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -92,9 +92,8 @@ enum report_mode { TOUCHPAD_REPORT_ALL = TOUCHPAD_REPORT_BUTTONS | TOUCHPAD_REPORT_CONTACTS, }; -#define MT_IO_FLAGS_RUNNING 0 -#define MT_IO_FLAGS_ACTIVE_SLOTS 1 -#define MT_IO_FLAGS_PENDING_SLOTS 2 +#define MT_IO_SLOTS_MASK GENMASK(7, 0) /* reserve first 8 bits for slot tracking */ +#define MT_IO_FLAGS_RUNNING 32 static const bool mtrue = true; /* default for true */ static const bool mfalse; /* default for false */ @@ -169,7 +168,11 @@ struct mt_device { struct mt_class mtclass; /* our mt device class */ struct timer_list release_timer; /* to release sticky fingers */ struct hid_device *hdev; /* hid_device we're attached to */ - unsigned long mt_io_flags; /* mt flags (MT_IO_FLAGS_*) */ + unsigned long mt_io_flags; /* mt flags (MT_IO_FLAGS_RUNNING) + * first 8 bits are reserved for keeping the slot + * states, this is fine because we only support up + * to 250 slots (MT_MAX_MAXCONTACT) + */ __u8 inputmode_value; /* InputMode HID feature value */ __u8 maxcontacts; bool is_buttonpad; /* is this device a button pad? */ @@ -977,6 +980,7 @@ static void mt_release_pending_palms(str for_each_set_bit(slotnum, app->pending_palm_slots, td->maxcontacts) { clear_bit(slotnum, app->pending_palm_slots); + clear_bit(slotnum, &td->mt_io_flags); input_mt_slot(input, slotnum); input_mt_report_slot_inactive(input); @@ -1008,12 +1012,6 @@ static void mt_sync_frame(struct mt_devi app->num_received = 0; app->left_button_state = 0; - - if (test_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags)) - set_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags); - else - clear_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags); - clear_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags); } static int mt_compute_timestamp(struct mt_application *app, __s32 value) @@ -1188,7 +1186,9 @@ static int mt_process_slot(struct mt_dev input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major); input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor); - set_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags); + set_bit(slotnum, &td->mt_io_flags); + } else { + clear_bit(slotnum, &td->mt_io_flags); } return 0; @@ -1323,7 +1323,7 @@ static void mt_touch_report(struct hid_d * defect. */ if (app->quirks & MT_QUIRK_STICKY_FINGERS) { - if (test_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags)) + if (td->mt_io_flags & MT_IO_SLOTS_MASK) mod_timer(&td->release_timer, jiffies + msecs_to_jiffies(100)); else @@ -1782,6 +1782,7 @@ static void mt_release_contacts(struct h for (i = 0; i < mt->num_slots; i++) { input_mt_slot(input_dev, i); input_mt_report_slot_inactive(input_dev); + clear_bit(i, &td->mt_io_flags); } input_mt_sync_frame(input_dev); input_sync(input_dev); @@ -1804,7 +1805,7 @@ static void mt_expired_timeout(struct ti */ if (test_and_set_bit_lock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags)) return; - if (test_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags)) + if (td->mt_io_flags & MT_IO_SLOTS_MASK) mt_release_contacts(hdev); clear_bit_unlock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags); }