1 files changed, 41 insertions, 39 deletions

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 11979be33589..b18c63a3f2ab 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -378,11 +378,8 @@ static struct attribute_group ads7845_attr_group = {
 static void ads7846_rx(void *ads)
 {
         struct ads7846          *ts = ads;
-        struct input_dev        *input_dev = ts->input;
         unsigned                Rt;
-        unsigned                sync = 0;
         u16                     x, y, z1, z2;
-        unsigned long           flags;
 
         /* ads7846_rx_val() did in-place conversion (including byteswap) from
          * on-the-wire format as part of debouncing to get stable readings.
@@ -396,7 +393,7 @@ static void ads7846_rx(void *ads)
         if (x == MAX_12BIT)
                 x = 0;
 
-        if (likely(x && z1 && !device_suspended(&ts->spi->dev))) {
+        if (likely(x && z1)) {
                 /* compute touch pressure resistance using equation #2 */
                 Rt = z2;
                 Rt -= z1;
@@ -412,52 +409,44 @@ static void ads7846_rx(void *ads)
          * once more the measurement
          */
         if (ts->tc.ignore || Rt > ts->pressure_max) {
+#ifdef VERBOSE
+                pr_debug("%s: ignored %d pressure %d\n",
+                        ts->spi->dev.bus_id, ts->tc.ignore, Rt);
+#endif
                 hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
                               HRTIMER_REL);
                 return;
         }
 
-        /* NOTE:  "pendown" is inferred from pressure; we don't rely on
-         * being able to check nPENIRQ status, or "friendly" trigger modes
-         * (both-edges is much better than just-falling or low-level).
-         *
-         * REVISIT:  some boards may require reading nPENIRQ; it's
-         * needed on 7843.  and 7845 reads pressure differently...
+        /* NOTE: We can't rely on the pressure to determine the pen down
+         * state, even this controller has a pressure sensor.  The pressure
+         * value can fluctuate for quite a while after lifting the pen and
+         * in some cases may not even settle at the expected value.
          *
-         * REVISIT:  the touchscreen might not be connected; this code
-         * won't notice that, even if nPENIRQ never fires ...
+         * The only safe way to check for the pen up condition is in the
+         * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
          */
-        if (!ts->pendown && Rt != 0) {
-                input_report_key(input_dev, BTN_TOUCH, 1);
-                sync = 1;
-        } else if (ts->pendown && Rt == 0) {
-                input_report_key(input_dev, BTN_TOUCH, 0);
-                sync = 1;
-        }
-
         if (Rt) {
-                input_report_abs(input_dev, ABS_X, x);
-                input_report_abs(input_dev, ABS_Y, y);
-                sync = 1;
-        }
+                struct input_dev *input = ts->input;
 
-        if (sync) {
-                input_report_abs(input_dev, ABS_PRESSURE, Rt);
-                input_sync(input_dev);
-        }
-
-#ifdef  VERBOSE
-        if (Rt || ts->pendown)
-                pr_debug("%s: %d/%d/%d%s\n", ts->spi->dev.bus_id,
-                        x, y, Rt, Rt ? "" : " UP");
+                if (!ts->pendown) {
+                        input_report_key(input, BTN_TOUCH, 1);
+                        ts->pendown = 1;
+#ifdef VERBOSE
+                        dev_dbg(&ts->spi->dev, "DOWN\n");
 #endif
+                }
+                input_report_abs(input, ABS_X, x);
+                input_report_abs(input, ABS_Y, y);
+                input_report_abs(input, ABS_PRESSURE, Rt);
 
-        spin_lock_irqsave(&ts->lock, flags);
+                input_sync(input);
+#ifdef VERBOSE
+                dev_dbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
+#endif
+        }
 
-        ts->pendown = (Rt != 0);
         hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), HRTIMER_REL);
-
-        spin_unlock_irqrestore(&ts->lock, flags);
 }
 
 static int ads7846_debounce(void *ads, int data_idx, int *val)
@@ -553,14 +542,27 @@ static int ads7846_timer(struct hrtimer *handle)
 
         spin_lock_irq(&ts->lock);
 
-        if (unlikely(ts->msg_idx && !ts->pendown)) {
+        if (unlikely(!ts->get_pendown_state() ||
+                     device_suspended(&ts->spi->dev))) {
+                if (ts->pendown) {
+                        struct input_dev *input = ts->input;
+
+                        input_report_key(input, BTN_TOUCH, 0);
+                        input_report_abs(input, ABS_PRESSURE, 0);
+                        input_sync(input);
+
+                        ts->pendown = 0;
+#ifdef VERBOSE
+                        dev_dbg(&ts->spi->dev, "UP\n");
+#endif
+                }
+
                 /* measurement cycle ended */
                 if (!device_suspended(&ts->spi->dev)) {
                         ts->irq_disabled = 0;
                         enable_irq(ts->spi->irq);
                 }
                 ts->pending = 0;
-                ts->msg_idx = 0;
         } else {
                 /* pen is still down, continue with the measurement */
                 ts->msg_idx = 0;