Linux v4.15

1 files changed, 106 insertions, 0 deletions

diff --git a/0001-HID-multitouch-Properly-deal-with-Win8-PTP-reports-w.patch b/0001-HID-multitouch-Properly-deal-with-Win8-PTP-reports-w.patch
new file mode 100644
index 000000000..e15ec6bb1
--- /dev/null
+++ b/0001-HID-multitouch-Properly-deal-with-Win8-PTP-reports-w.patch
@@ -0,0 +1,106 @@
+From f5c1da991de077420fda17a236342de5a0068f5d Mon Sep 17 00:00:00 2001
+From: Hans de Goede <hdegoede@redhat.com>
+Date: Wed, 22 Nov 2017 12:57:08 +0100
+Subject: [PATCH v2 1/3] HID: multitouch: Properly deal with Win8 PTP reports
+ with 0 touches
+
+The Windows Precision Touchpad spec "Figure 4 Button Only Down and Up"
+and "Table 9 Report Sequence for Button Only Down and Up" indicate
+that the first packet of a (possibly hybrid mode multi-packet) frame
+may contain a contact-count of 0 if only a button is pressed and no
+fingers are detected.
+
+This means that a value of 0 for contact-count is a valid value and
+should be used as expected contact count when it is the first packet
+(num_received == 0), as extra check to make sure that this is the first
+packet of a buttons only frame, we also check that the timestamp is
+different.
+
+Signed-off-by: Hans de Goede <hdegoede@redhat.com>
+Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
+Signed-off-by: Jiri Kosina <jkosina@suse.cz>
+---
+ drivers/hid/hid-multitouch.c | 32 ++++++++++++++++++++++++++++++--
+ 1 file changed, 30 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
+index 9ef24b518f12..d8b1cad74faf 100644
+--- a/drivers/hid/hid-multitouch.c
++++ b/drivers/hid/hid-multitouch.c
+@@ -119,6 +119,9 @@ struct mt_device {
+ 	unsigned long mt_io_flags;	/* mt flags (MT_IO_FLAGS_*) */
+ 	int cc_index;	/* contact count field index in the report */
+ 	int cc_value_index;	/* contact count value index in the field */
++	int scantime_index;	/* scantime field index in the report */
++	int scantime_val_index;	/* scantime value index in the field */
++	int prev_scantime;	/* scantime reported in the previous packet */
+ 	unsigned last_slot_field;	/* the last field of a slot */
+ 	unsigned mt_report_id;	/* the report ID of the multitouch device */
+ 	unsigned long initial_quirks;	/* initial quirks state */
+@@ -599,6 +602,12 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+ 				EV_MSC, MSC_TIMESTAMP);
+ 			input_set_capability(hi->input, EV_MSC, MSC_TIMESTAMP);
+ 			mt_store_field(usage, td, hi);
++			/* Ignore if indexes are out of bounds. */
++			if (field->index >= field->report->maxfield ||
++			    usage->usage_index >= field->report_count)
++				return 1;
++			td->scantime_index = field->index;
++			td->scantime_val_index = usage->usage_index;
+ 			return 1;
+ 		case HID_DG_CONTACTCOUNT:
+ 			/* Ignore if indexes are out of bounds. */
+@@ -855,9 +864,10 @@ static void mt_process_mt_event(struct hid_device *hid, struct hid_field *field,
+ static void mt_touch_report(struct hid_device *hid, struct hid_report *report)
+ {
+ 	struct mt_device *td = hid_get_drvdata(hid);
++	__s32 cls = td->mtclass.name;
+ 	struct hid_field *field;
+ 	unsigned count;
+-	int r, n;
++	int r, n, scantime = 0;
+ 
+ 	/* sticky fingers release in progress, abort */
+ 	if (test_and_set_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags))
+@@ -867,12 +877,29 @@ static void mt_touch_report(struct hid_device *hid, struct hid_report *report)
+ 	 * Includes multi-packet support where subsequent
+ 	 * packets are sent with zero contactcount.
+ 	 */
++	if (td->scantime_index >= 0) {
++		field = report->field[td->scantime_index];
++		scantime = field->value[td->scantime_val_index];
++	}
+ 	if (td->cc_index >= 0) {
+ 		struct hid_field *field = report->field[td->cc_index];
+ 		int value = field->value[td->cc_value_index];
+-		if (value)
++
++		/*
++		 * For Win8 PTPs the first packet (td->num_received == 0) may
++		 * have a contactcount of 0 if there only is a button event.
++		 * We double check that this is not a continuation packet
++		 * of a possible multi-packet frame be checking that the
++		 * timestamp has changed.
++		 */
++		if ((cls == MT_CLS_WIN_8 || cls == MT_CLS_WIN_8_DUAL) &&
++		    td->num_received == 0 && td->prev_scantime != scantime)
++			td->num_expected = value;
++		/* A non 0 contact count always indicates a first packet */
++		else if (value)
+ 			td->num_expected = value;
+ 	}
++	td->prev_scantime = scantime;
+ 
+ 	for (r = 0; r < report->maxfield; r++) {
+ 		field = report->field[r];
+@@ -1329,6 +1356,7 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
+ 	td->maxcontact_report_id = -1;
+ 	td->inputmode_value = MT_INPUTMODE_TOUCHSCREEN;
+ 	td->cc_index = -1;
++	td->scantime_index = -1;
+ 	td->mt_report_id = -1;
+ 	hid_set_drvdata(hdev, td);
+ 
+-- 
+2.14.3
+