From e27bfc22bba932950a398b32bf57be6f825438ee Mon Sep 17 00:00:00 2001

From: Bastien Nocera <hadess@hadess.net>

Date: Tue, 8 Jul 2014 18:29:06 +0200

Subject: [PATCH] accelerometer: Don't wait for new data from the sensor

Instead of waiting for new data from the sensor, which might be

a long time coming, depending on the sensor device, ask the kernel

for the last state for that particular input device.

(cherry picked from commit a545c6e1aa31b4d7e80c9d3609d9fc4fc9921498)

---

 src/udev/accelerometer/accelerometer.c | 33 ++++++---------------------------

 1 file changed, 6 insertions(+), 27 deletions(-)

diff --git a/src/udev/accelerometer/accelerometer.c b/src/udev/accelerometer/accelerometer.c

index 925d38de1f..32adf27777 100644

--- a/src/udev/accelerometer/accelerometer.c

+++ b/src/udev/accelerometer/accelerometer.c

@@ -180,7 +180,7 @@ get_prev_orientation(struct udev_device *dev)

         return string_to_orientation(value);

 }

-#define SET_AXIS(axis, code_) if (ev[i].code == code_) { if (got_##axis == 0) { axis = ev[i].value; got_##axis = true; } }

+#define READ_AXIS(axis, var) { memzero(&abs_info, sizeof(abs_info)); r = ioctl(fd, EVIOCGABS(axis), &abs_info); if (r < 0) return; var = abs_info.value; }

 /* accelerometers */

 static void test_orientation(struct udev *udev,

@@ -189,10 +189,9 @@ static void test_orientation(struct udev *udev,

 {

         OrientationUp old, new;

         _cleanup_close_ int fd = -1;

-        struct input_event ev[64];

-        bool got_syn = false;

-        bool got_x = false, got_y = false, got_z = false;

+        struct input_absinfo abs_info;

         int x = 0, y = 0, z = 0;

+        int r;

         char text[64];

         old = get_prev_orientation(dev);

@@ -201,30 +200,10 @@ static void test_orientation(struct udev *udev,

         if (fd < 0)

                 return;

-        while (1) {

-                int i, r;

-

-                r = read(fd, ev, sizeof(struct input_event) * 64);

-

-                if (r < (int) sizeof(struct input_event))

-                        return;

-

-                for (i = 0; i < r / (int) sizeof(struct input_event); i++) {

-                        if (got_syn) {

-                                if (ev[i].type == EV_ABS) {

-                                        SET_AXIS(x, ABS_X);

-                                        SET_AXIS(y, ABS_Y);

-                                        SET_AXIS(z, ABS_Z);

-                                }

-                        }

-                        if (ev[i].type == EV_SYN && ev[i].code == SYN_REPORT)

-                                got_syn = true;

-                        if (got_x && got_y && got_z)

-                                goto read_dev;

-                }

-        }

+        READ_AXIS(ABS_X, x);

+        READ_AXIS(ABS_Y, y);

+        READ_AXIS(ABS_Z, z);

-read_dev:

         new = orientation_calc(old, x, y, z);

         snprintf(text, sizeof(text),

                  "ID_INPUT_ACCELEROMETER_ORIENTATION=%s", orientation_to_string(new));