[PATCH 4.14 030/109] HID: multitouch: Only look at non touch fields in first packet of a frame

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

--

From: Hans de Goede 


[ Upstream commit 55746d28d66860bccaae20a67b55b9d5db7c14af ]

Devices in "single finger hybrid mode" will send one report per finger,
on some devices only the first report of such a multi-packet frame will
contain a value for BTN_LEFT, in subsequent reports (if multiple fingers
are down) the value is always 0, causing hid-mt to report BTN_LEFT going
1 - 0 - 1 - 0 when pressing a clickpad and putting down a second finger.
This happens for example on USB 0603:0002 mt touchpads.

This commit fixes this by only reporting non touch fields for the first
packet of a (possibly) multi-packet frame.

Signed-off-by: Hans de Goede 
Reviewed-by: Benjamin Tissoires 
Signed-off-by: Jiri Kosina 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/hid/hid-multitouch.c |   17 +++--
 1 file changed, 15 insertions(+), 2 deletions(-)

--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -738,9 +738,11 @@ static int mt_touch_event(struct hid_dev
 }
 
 static void mt_process_mt_event(struct hid_device *hid, struct hid_field 
*field,
-   struct hid_usage *usage, __s32 value)
+   struct hid_usage *usage, __s32 value,
+   bool first_packet)
 {
struct mt_device *td = hid_get_drvdata(hid);
+   __s32 cls = td->mtclass.name;
__s32 quirks = td->mtclass.quirks;
struct input_dev *input = field->hidinput->input;
 
@@ -794,6 +796,15 @@ static void mt_process_mt_event(struct h
break;
 
default:
+   /*
+* For Win8 PTP touchpads we should only look at
+* non finger/touch events in the first_packet of
+* a (possible) multi-packet frame.
+*/
+   if ((cls == MT_CLS_WIN_8 || cls == MT_CLS_WIN_8_DUAL) &&
+   !first_packet)
+   return;
+
if (usage->type)
input_event(input, usage->type, usage->code,
value);
@@ -813,6 +824,7 @@ static void mt_touch_report(struct hid_d
 {
struct mt_device *td = hid_get_drvdata(hid);
struct hid_field *field;
+   bool first_packet;
unsigned count;
int r, n;
 
@@ -831,6 +843,7 @@ static void mt_touch_report(struct hid_d
td->num_expected = value;
}
 
+   first_packet = td->num_received == 0;
for (r = 0; r < report->maxfield; r++) {
field = report->field[r];
count = field->report_count;
@@ -840,7 +853,7 @@ static void mt_touch_report(struct hid_d
 
for (n = 0; n < count; n++)
mt_process_mt_event(hid, field, >usage[n],
-   field->value[n]);
+   field->value[n], first_packet);
}
 
if (td->num_received >= td->num_expected)

[PATCH 4.14 030/109] HID: multitouch: Only look at non touch fields in first packet of a frame

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

--

From: Hans de Goede 


[ Upstream commit 55746d28d66860bccaae20a67b55b9d5db7c14af ]

Devices in "single finger hybrid mode" will send one report per finger,
on some devices only the first report of such a multi-packet frame will
contain a value for BTN_LEFT, in subsequent reports (if multiple fingers
are down) the value is always 0, causing hid-mt to report BTN_LEFT going
1 - 0 - 1 - 0 when pressing a clickpad and putting down a second finger.
This happens for example on USB 0603:0002 mt touchpads.

This commit fixes this by only reporting non touch fields for the first
packet of a (possibly) multi-packet frame.

Signed-off-by: Hans de Goede 
Reviewed-by: Benjamin Tissoires 
Signed-off-by: Jiri Kosina 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/hid/hid-multitouch.c |   17 +++--
 1 file changed, 15 insertions(+), 2 deletions(-)

--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -738,9 +738,11 @@ static int mt_touch_event(struct hid_dev
 }
 
 static void mt_process_mt_event(struct hid_device *hid, struct hid_field 
*field,
-   struct hid_usage *usage, __s32 value)
+   struct hid_usage *usage, __s32 value,
+   bool first_packet)
 {
struct mt_device *td = hid_get_drvdata(hid);
+   __s32 cls = td->mtclass.name;
__s32 quirks = td->mtclass.quirks;
struct input_dev *input = field->hidinput->input;
 
@@ -794,6 +796,15 @@ static void mt_process_mt_event(struct h
break;
 
default:
+   /*
+* For Win8 PTP touchpads we should only look at
+* non finger/touch events in the first_packet of
+* a (possible) multi-packet frame.
+*/
+   if ((cls == MT_CLS_WIN_8 || cls == MT_CLS_WIN_8_DUAL) &&
+   !first_packet)
+   return;
+
if (usage->type)
input_event(input, usage->type, usage->code,
value);
@@ -813,6 +824,7 @@ static void mt_touch_report(struct hid_d
 {
struct mt_device *td = hid_get_drvdata(hid);
struct hid_field *field;
+   bool first_packet;
unsigned count;
int r, n;
 
@@ -831,6 +843,7 @@ static void mt_touch_report(struct hid_d
td->num_expected = value;
}
 
+   first_packet = td->num_received == 0;
for (r = 0; r < report->maxfield; r++) {
field = report->field[r];
count = field->report_count;
@@ -840,7 +853,7 @@ static void mt_touch_report(struct hid_d
 
for (n = 0; n < count; n++)
mt_process_mt_event(hid, field, >usage[n],
-   field->value[n]);
+   field->value[n], first_packet);
}
 
if (td->num_received >= td->num_expected)