--- v5
+++ v2
@@ -1,343 +1,70 @@
-Synaptics image sensor touchpads track 5 fingers, but only report 2.
-This patch attempts to deal with some idiosyncrasies of these touchpads:
+From: Daniel Kurtz <djkurtz@chromium.org>
- * When there are 3 or more fingers, only two are reported.
- * The touchpad tracks the 5 fingers in slot[0] through slot[4].
- * It always reports the lowest and highest valid slots in SGM and AGM
- packets, respectively.
- * The number of fingers is only reported in the SGM packet. However,
- the number of fingers can change either before or after an AGM
- packet.
- * Thus, if an SGM reports a different number of fingers than the last
- SGM, it is impossible to tell whether the intervening AGM corresponds
- to the old number of fingers or the new number of fingers.
- * For example, when going from 2->3 fingers, it is not possible to tell
- whether tell AGM contains slot[1] (old 2nd finger) or slot[2] (new
- 3rd finger).
- * When fingers are added one at at time, from 1->2->3, it is possible to
- track which slots are contained in the SGM and AGM packets:
- 1 finger: SGM = slot[0], no AGM
- 2 fingers: SGM = slot[0], AGM = slot[1]
- 3 fingers: SGM = slot[0], AGM = slot[2]
- * It is also possible to track which slot is contained in the SGM when 1
- of 2 fingers is removed. This is because the touchpad sends a special
- (0,0,0) AGM packet whenever all fingers are removed except slot[0]:
- Last AGM == (0,0,0): SGM contains slot[1]
- Else: SGM contains slot[0]
- * However, once there are 3 fingers, if exactly 1 finger is removed, it
- is impossible to tell which 2 slots are contained in SGM and AGM.
- The (SGM,AGM) could be (0,1), (0,2), or (1,2). There is no way to know.
- * Similarly, if two fingers are simultaneously removed (3->1), then it
- is only possible to know if SGM still contains slot[0].
- * Since it is not possible to reliably track which slot is being
- reported, we invalidate the tracking_id every time the number of
- fingers changes until this ambiguity is resolved when:
- a) All fingers are removed.
- b) 4 or 5 fingers are touched, generates an AGM-CONTACT packet.
- c) All fingers are removed except slot[0]. In this special case, the
- ambiguity is resolved since by the (0,0,0) AGM packet.
+As long as we know which slots are currently contained in SGM and AGM
+packets, it is possible to track the slot 0 finger when transitioning from
+2->3 fingers. This is the case when fingers are being added one at a
+time, 1->2->3.
-Behavior of the driver:
-
-When 2 or more fingers are present on the touchpad, the kernel reports
-up to two MT-B slots containing the position data for two of the fingers
-reported by the touchpad. If the identity of a finger cannot be tracked
-when the number-of-fingers changes, the corresponding MT-B slot will be
-invalidated (track_id set to -1), and a new track_id will be assigned in
-a subsequent input event report.
-
-The driver always reports the total number of fingers using one of the
-EV_KEY/BTN_TOOL_*TAP events. This could differ from the number of valid
-MT-B slots for two reasons:
- a) There are more than 2 fingers on the pad.
- b) During ambiguous number-of-fingers transitions, the correct track_id
- for one or both of the slots cannot be determined, so the slots are
- invalidated.
-
-Thus, this is a hybrid singletouch/MT-B scheme. Userspace can detect
-this behavior by noting that the driver supports more EV_KEY/BTN_TOOL_*TAP
-events than its maximum EV_ABS/ABS_MT_SLOT.
+However, when fingers are removed, we sometimes lose track of which slots
+are contained in SGM and AGM. In particular, when transitioning from 3->2
+and sometimes 3->1. In both of these cases, we can no longer track slot 0
+during 2->3 transitions.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
-Acked-by: Chase Douglas <chase.douglas@canonical.com>
---
- drivers/input/mouse/synaptics.c | 290 ++++++++++++++++++++++++++++++++++++--
- drivers/input/mouse/synaptics.h | 4 +
- 2 files changed, 278 insertions(+), 16 deletions(-)
+ drivers/input/mouse/synaptics.c | 33 +++++++++++++++++++++++++++------
+ drivers/input/mouse/synaptics.h | 1 +
+ 2 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
-index 8a025a6..a5bc469 100644
+index b626b98..893e567 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
-@@ -453,6 +453,9 @@ static void synaptics_parse_agm(const unsigned char buf[],
- default:
+@@ -659,6 +659,7 @@ static void synaptics_image_sensor_0f(struct synaptics_data *priv,
+ struct synaptics_mt_state *mt_state)
+ {
+ synaptics_mt_state_set(mt_state, 0, -1, -1);
++ priv->mt_state_lost = false;
+ }
+
+ /* Handle case where mt_state->count = 1 */
+@@ -726,6 +727,7 @@ static void synaptics_image_sensor_1f(struct synaptics_data *priv,
+ * So, empty all slots. We will guess slot 0 on subsequent 1->1
+ */
+ synaptics_mt_state_set(mt_state, 0, -1, -1);
++ priv->mt_state_lost = true;
break;
}
-+
-+ /* Record that at least one AGM has been received since last SGM */
-+ priv->agm_pending = true;
}
-
- static int synaptics_parse_hw_state(const unsigned char buf[],
-@@ -606,26 +609,53 @@ static void synaptics_report_slot(struct input_dev *dev, int slot,
- }
-
- static void synaptics_report_mt_data(struct psmouse *psmouse,
-- int count,
-+ struct synaptics_mt_state *mt_state,
- const struct synaptics_hw_state *sgm)
- {
- struct input_dev *dev = psmouse->dev;
- struct synaptics_data *priv = psmouse->private;
- struct synaptics_hw_state *agm = &priv->agm;
-+ struct synaptics_mt_state *old = &priv->mt_state;
-
-- switch (count) {
-+ switch (mt_state->count) {
- case 0:
- synaptics_report_slot(dev, 0, NULL);
- synaptics_report_slot(dev, 1, NULL);
- break;
- case 1:
-- synaptics_report_slot(dev, 0, sgm);
-- synaptics_report_slot(dev, 1, NULL);
-+ if (mt_state->sgm == -1) {
-+ synaptics_report_slot(dev, 0, NULL);
-+ synaptics_report_slot(dev, 1, NULL);
-+ } else if (mt_state->sgm == 0) {
-+ synaptics_report_slot(dev, 0, sgm);
-+ synaptics_report_slot(dev, 1, NULL);
-+ } else {
-+ synaptics_report_slot(dev, 0, NULL);
-+ synaptics_report_slot(dev, 1, sgm);
-+ }
- break;
-- case 2:
-- case 3: /* Fall-through case */
-- synaptics_report_slot(dev, 0, sgm);
-- synaptics_report_slot(dev, 1, agm);
-+ default:
-+ /*
-+ * If the finger slot contained in SGM is valid, and either
-+ * hasn't changed, or is new, then report SGM in MTB slot 0.
-+ * Otherwise, empty MTB slot 0.
-+ */
-+ if (mt_state->sgm != -1 &&
-+ (mt_state->sgm == old->sgm || old->sgm == -1))
-+ synaptics_report_slot(dev, 0, sgm);
-+ else
-+ synaptics_report_slot(dev, 0, NULL);
-+
-+ /*
-+ * If the finger slot contained in AGM is valid, and either
-+ * hasn't changed, or is new, then report AGM in MTB slot 1.
-+ * Otherwise, empty MTB slot 1.
-+ */
-+ if (mt_state->agm != -1 &&
-+ (mt_state->agm == old->agm || old->agm == -1))
-+ synaptics_report_slot(dev, 1, agm);
-+ else
-+ synaptics_report_slot(dev, 1, NULL);
+@@ -771,6 +773,7 @@ static void synaptics_image_sensor_2f(struct synaptics_data *priv,
+ * subsequent 2->2
+ */
+ synaptics_mt_state_set(mt_state, 0, -1, -1);
++ priv->mt_state_lost = true;
break;
}
-
-@@ -633,29 +663,257 @@ static void synaptics_report_mt_data(struct psmouse *psmouse,
- input_mt_report_pointer_emulation(dev, false);
-
- /* Send the number of fingers reported by touchpad itself. */
-- input_mt_report_finger_count(dev, count);
-+ input_mt_report_finger_count(dev, mt_state->count);
-
- synaptics_report_buttons(psmouse, sgm);
-
- input_sync(dev);
}
-
-+/* Handle case where mt_state->count = 0 */
-+static void synaptics_image_sensor_0f(struct synaptics_data *priv,
-+ struct synaptics_mt_state *mt_state)
-+{
-+ synaptics_mt_state_set(mt_state, 0, -1, -1);
-+ priv->mt_state_lost = false;
-+}
-+
-+/* Handle case where mt_state->count = 1 */
-+static void synaptics_image_sensor_1f(struct synaptics_data *priv,
-+ struct synaptics_mt_state *mt_state)
-+{
-+ struct synaptics_hw_state *agm = &priv->agm;
-+ struct synaptics_mt_state *old = &priv->mt_state;
-+
-+ /*
-+ * If the last AGM was (0,0,0), and there is only one finger left,
-+ * then we absolutely know that SGM contains slot 0, and all other
-+ * fingers have been removed.
-+ */
-+ if (priv->agm_pending && agm->z == 0) {
-+ synaptics_mt_state_set(mt_state, 1, 0, -1);
-+ priv->mt_state_lost = false;
-+ return;
-+ }
-+
-+ switch (old->count) {
-+ case 0:
-+ synaptics_mt_state_set(mt_state, 1, 0, -1);
-+ break;
-+ case 1:
-+ /*
-+ * If mt_state_lost, then the previous transition was 3->1,
-+ * and SGM now contains either slot 0 or 1, but we don't know
-+ * which. So, we just assume that the SGM now contains slot 1.
-+ *
-+ * If pending AGM and either:
-+ * (a) the previous SGM slot contains slot 0, or
-+ * (b) there was no SGM slot
-+ * then, the SGM now contains slot 1
-+ *
-+ * Case (a) happens with very rapid "drum roll" gestures, where
-+ * slot 0 finger is lifted and a new slot 1 finger touches
-+ * within one reporting interval.
-+ *
-+ * Case (b) happens if initially two or more fingers tap
-+ * briefly, and all but one lift before the end of the first
-+ * reporting interval.
-+ *
-+ * (In both these cases, slot 0 will becomes empty, so SGM
-+ * contains slot 1 with the new finger)
-+ *
-+ * Else, if there was no previous SGM, it now contains slot 0.
-+ *
-+ * Otherwise, SGM still contains the same slot.
-+ */
-+ if (priv->mt_state_lost ||
-+ (priv->agm_pending && old->sgm <= 0))
-+ synaptics_mt_state_set(mt_state, 1, 1, -1);
-+ else if (old->sgm == -1)
-+ synaptics_mt_state_set(mt_state, 1, 0, -1);
-+ break;
-+ case 2:
-+ /*
-+ * If mt_state_lost, we don't know which finger SGM contains.
-+ *
-+ * So, report 1 finger, but with both slots empty.
-+ * We will use slot 1 on subsequent 1->1
-+ */
-+ if (priv->mt_state_lost) {
-+ synaptics_mt_state_set(mt_state, 1, -1, -1);
-+ break;
-+ }
-+ /*
-+ * Since the last AGM was NOT (0,0,0), it was the finger in
-+ * slot 0 that has been removed.
-+ * So, SGM now contains previous AGM's slot, and AGM is now
-+ * empty.
-+ */
-+ synaptics_mt_state_set(mt_state, 1, old->agm, -1);
-+ break;
-+ case 3:
-+ /*
-+ * Since last AGM was not (0,0,0), we don't know which finger
-+ * is left.
-+ *
-+ * So, report 1 finger, but with both slots empty.
-+ * We will use slot 1 on subsequent 1->1
-+ */
-+ synaptics_mt_state_set(mt_state, 1, -1, -1);
-+ priv->mt_state_lost = true;
-+ break;
-+ }
-+}
-+
-+/* Handle case where mt_state->count = 2 */
-+static void synaptics_image_sensor_2f(struct synaptics_data *priv,
-+ struct synaptics_mt_state *mt_state)
-+{
-+ struct synaptics_mt_state *old = &priv->mt_state;
-+
-+ switch (old->count) {
-+ case 0:
-+ synaptics_mt_state_set(mt_state, 2, 0, 1);
-+ break;
-+ case 1:
-+ /*
-+ * If previous SGM contained slot 1 or higher, SGM now contains
-+ * slot 0 (the newly touching finger) and AGM contains SGM's
-+ * previous slot.
-+ *
-+ * Otherwise, SGM still contains slot 0 and AGM now contains
-+ * slot 1.
-+ */
-+ if (old->sgm >= 1)
-+ synaptics_mt_state_set(mt_state, 2, 0, old->sgm);
-+ else
-+ synaptics_mt_state_set(mt_state, 2, 0, 1);
-+ break;
-+ case 2:
-+ /*
-+ * If mt_state_lost, SGM now contains either finger 1 or 2, but
-+ * we don't know which.
-+ * So, we just assume that the SGM contains slot 0 and AGM 1.
-+ */
-+ if (priv->mt_state_lost)
-+ synaptics_mt_state_set(mt_state, 2, 0, 1);
-+ /*
-+ * Otherwise, use the same mt_state, since it either hasn't
-+ * changed, or was updated by a recently received AGM-CONTACT
-+ * packet.
-+ */
-+ break;
-+ case 3:
-+ /*
-+ * 3->2 transitions have two unsolvable problems:
-+ * 1) no indication is given which finger was removed
-+ * 2) no way to tell if agm packet was for finger 3
-+ * before 3->2, or finger 2 after 3->2.
-+ *
-+ * So, report 2 fingers, but empty all slots.
-+ * We will guess slots [0,1] on subsequent 2->2.
-+ */
-+ synaptics_mt_state_set(mt_state, 2, -1, -1);
-+ priv->mt_state_lost = true;
-+ break;
-+ }
-+}
-+
-+/* Handle case where mt_state->count = 3 */
-+static void synaptics_image_sensor_3f(struct synaptics_data *priv,
-+ struct synaptics_mt_state *mt_state)
-+{
-+ struct synaptics_mt_state *old = &priv->mt_state;
-+
-+ switch (old->count) {
-+ case 0:
-+ synaptics_mt_state_set(mt_state, 3, 0, 2);
-+ break;
-+ case 1:
-+ /*
-+ * If previous SGM contained slot 2 or higher, SGM now contains
-+ * slot 0 (one of the newly touching fingers) and AGM contains
-+ * SGM's previous slot.
-+ *
-+ * Otherwise, SGM now contains slot 0 and AGM contains slot 2.
-+ */
-+ if (old->sgm >= 2)
-+ synaptics_mt_state_set(mt_state, 3, 0, old->sgm);
-+ else
-+ synaptics_mt_state_set(mt_state, 3, 0, 2);
-+ break;
-+ case 2:
-+ /*
+@@ -800,14 +803,32 @@ static void synaptics_image_sensor_3f(struct synaptics_data *priv,
+ break;
+ case 2:
+ /*
+- * On 2->3 transitions, we are given no indication which finger
+- * was added.
+- * We don't even know what finger the current AGM packet
+- * contained.
+ * After some 3->1 and all 3->2 transitions, we lose track
-+ * of which slot is reported by SGM and AGM.
-+ *
-+ * For 2->3 in this state, report 3 fingers, but empty all
-+ * slots, and we will guess (0,2) on a subsequent 0->3.
++ * of which slot is reported by sgm and agm.
+ *
+- * So, empty all slots. They get filled on a subsequent 3->3
++ * For 2->3 in this state, empty all slots, and we will guess
++ * (0,1) on a subsequent 0->3.
+ *
+ * To userspace, the resulting transition will look like:
-+ * 2:[0,1] -> 3:[-1,-1] -> 3:[0,2]
-+ */
++ * 2:[0,1] -> 0:[-1,-1] -> 3:[0,2]
+ */
+- synaptics_mt_state_set(mt_state, 0, -1, -1);
+ if (priv->mt_state_lost) {
-+ synaptics_mt_state_set(mt_state, 3, -1, -1);
++ synaptics_mt_state_set(mt_state, 0, -1, -1);
+ break;
+ }
+
@@ -350,83 +77,23 @@
+ * Subsequent AGMs will be reporting slot 2.
+ *
+ * To userspace, the resulting transition will look like:
-+ * 2:[0,1] -> 3:[0,-1] -> 3:[0,2]
++ * 2:[0,1] -> 1:[0,-1] -> 3:[0,2]
+ */
-+ synaptics_mt_state_set(mt_state, 3, 0, -1);
-+ break;
-+ case 3:
-+ /*
-+ * If, for whatever reason, the previous agm was invalid,
-+ * Assume SGM now contains slot 0, AGM now contains slot 2.
-+ */
-+ if (old->agm <= 2)
-+ synaptics_mt_state_set(mt_state, 3, 0, 2);
-+ /*
-+ * mt_state either hasn't changed, or was updated by a recently
-+ * received AGM-CONTACT packet.
-+ */
-+ break;
-+ }
-+}
-+
- static void synaptics_image_sensor_process(struct psmouse *psmouse,
- struct synaptics_hw_state *sgm)
- {
-- int count;
-+ struct synaptics_data *priv = psmouse->private;
-+ struct synaptics_hw_state *agm = &priv->agm;
-+ struct synaptics_mt_state mt_state;
-
-+ /* Initialize using current mt_state (as updated by last agm) */
-+ mt_state = agm->mt_state;
-+
-+ /*
-+ * Update mt_state using the new finger count and current mt_state.
-+ */
- if (sgm->z == 0)
-- count = 0;
-+ synaptics_image_sensor_0f(priv, &mt_state);
- else if (sgm->w >= 4)
-- count = 1;
-+ synaptics_image_sensor_1f(priv, &mt_state);
- else if (sgm->w == 0)
-- count = 2;
-- else
-- count = 3;
-+ synaptics_image_sensor_2f(priv, &mt_state);
-+ else if (sgm->w == 1)
-+ synaptics_image_sensor_3f(priv, &mt_state);
-
- /* Send resulting input events to user space */
-- synaptics_report_mt_data(psmouse, count, sgm);
-+ synaptics_report_mt_data(psmouse, &mt_state, sgm);
-+
-+ /* Store updated mt_state */
-+ priv->mt_state = agm->mt_state = mt_state;
-+ priv->agm_pending = false;
- }
-
- /*
++ synaptics_mt_state_set(mt_state, 1, 0, -1);
+ break;
+ case 3:
+ /*
diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h
-index 20f57df..622aea8 100644
+index 87be1fe..e3edfea 100644
--- a/drivers/input/mouse/synaptics.h
+++ b/drivers/input/mouse/synaptics.h
-@@ -161,11 +161,15 @@ struct synaptics_data {
-
+@@ -162,6 +162,7 @@ struct synaptics_data {
struct serio *pt_port; /* Pass-through serio port */
-+ struct synaptics_mt_state mt_state; /* Current mt finger state */
+ struct synaptics_mt_state mt_state; /* Current mt finger state */
+ bool mt_state_lost; /* mt_state may be incorrect */
-+
+
/*
* Last received Advanced Gesture Mode (AGM) packet. An AGM packet
- * contains position data for a second contact, at half resolution.
- */
- struct synaptics_hw_state agm;
-+ bool agm_pending; /* new AGM packet received */
- };
-
- void synaptics_module_init(void);
--
1.7.3.1
-