This is a note to let you know that I've just added the patch titled
iio: hid-sensors: Increase the precision of scale to fix wrong reading interpretation.
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iio-hid-sensors-increase-the-precision-of-scale-to-fix-wrong-reading-interpretation.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6f77199e9e4b84340c751c585691d7642a47d226 Mon Sep 17 00:00:00 2001
From: Song Hongyan <hongyan.song@xxxxxxxxx>
Date: Tue, 25 Oct 2016 01:30:07 +0000
Subject: iio: hid-sensors: Increase the precision of scale to fix wrong reading interpretation.
From: Song Hongyan <hongyan.song@xxxxxxxxx>
commit 6f77199e9e4b84340c751c585691d7642a47d226 upstream.
While testing, it was observed that on some platforms the scale value
from iio sysfs for gyroscope is always 0 (E.g. Yoga 260). This results
in the final angular velocity component values to be zeros.
This is caused by insufficient precision of scale value displayed in sysfs.
If the precision is changed to nano from current micro, then this is
sufficient to display the scale value on this platform.
Since this can be a problem for all other HID sensors, increase scale
precision of all HID sensors to nano from current micro.
Results on Yoga 260:
name scale before scale now
--------------------------------------------
gyro_3d 0.000000 0.000000174
als 0.001000 0.001000000
magn_3d 0.000001 0.000001000
accel_3d 0.000009 0.000009806
Signed-off-by: Song Hongyan <hongyan.song@xxxxxxxxx>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iio/common/hid-sensors/hid-sensor-attributes.c | 56 ++++++++---------
1 file changed, 28 insertions(+), 28 deletions(-)
--- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
@@ -30,26 +30,26 @@ static struct {
u32 usage_id;
int unit; /* 0 for default others from HID sensor spec */
int scale_val0; /* scale, whole number */
- int scale_val1; /* scale, fraction in micros */
+ int scale_val1; /* scale, fraction in nanos */
} unit_conversion[] = {
- {HID_USAGE_SENSOR_ACCEL_3D, 0, 9, 806650},
+ {HID_USAGE_SENSOR_ACCEL_3D, 0, 9, 806650000},
{HID_USAGE_SENSOR_ACCEL_3D,
HID_USAGE_SENSOR_UNITS_METERS_PER_SEC_SQRD, 1, 0},
{HID_USAGE_SENSOR_ACCEL_3D,
- HID_USAGE_SENSOR_UNITS_G, 9, 806650},
+ HID_USAGE_SENSOR_UNITS_G, 9, 806650000},
- {HID_USAGE_SENSOR_GYRO_3D, 0, 0, 17453},
+ {HID_USAGE_SENSOR_GYRO_3D, 0, 0, 17453293},
{HID_USAGE_SENSOR_GYRO_3D,
HID_USAGE_SENSOR_UNITS_RADIANS_PER_SECOND, 1, 0},
{HID_USAGE_SENSOR_GYRO_3D,
- HID_USAGE_SENSOR_UNITS_DEGREES_PER_SECOND, 0, 17453},
+ HID_USAGE_SENSOR_UNITS_DEGREES_PER_SECOND, 0, 17453293},
- {HID_USAGE_SENSOR_COMPASS_3D, 0, 0, 1000},
+ {HID_USAGE_SENSOR_COMPASS_3D, 0, 0, 1000000},
{HID_USAGE_SENSOR_COMPASS_3D, HID_USAGE_SENSOR_UNITS_GAUSS, 1, 0},
- {HID_USAGE_SENSOR_INCLINOMETER_3D, 0, 0, 17453},
+ {HID_USAGE_SENSOR_INCLINOMETER_3D, 0, 0, 17453293},
{HID_USAGE_SENSOR_INCLINOMETER_3D,
- HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453},
+ HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453293},
{HID_USAGE_SENSOR_INCLINOMETER_3D,
HID_USAGE_SENSOR_UNITS_RADIANS, 1, 0},
@@ -57,7 +57,7 @@ static struct {
{HID_USAGE_SENSOR_ALS, HID_USAGE_SENSOR_UNITS_LUX, 1, 0},
{HID_USAGE_SENSOR_PRESSURE, 0, 100, 0},
- {HID_USAGE_SENSOR_PRESSURE, HID_USAGE_SENSOR_UNITS_PASCAL, 0, 1000},
+ {HID_USAGE_SENSOR_PRESSURE, HID_USAGE_SENSOR_UNITS_PASCAL, 0, 1000000},
};
static int pow_10(unsigned power)
@@ -266,15 +266,15 @@ EXPORT_SYMBOL(hid_sensor_write_raw_hyst_
/*
* This fuction applies the unit exponent to the scale.
* For example:
- * 9.806650 ->exp:2-> val0[980]val1[665000]
- * 9.000806 ->exp:2-> val0[900]val1[80600]
- * 0.174535 ->exp:2-> val0[17]val1[453500]
- * 1.001745 ->exp:0-> val0[1]val1[1745]
- * 1.001745 ->exp:2-> val0[100]val1[174500]
- * 1.001745 ->exp:4-> val0[10017]val1[450000]
- * 9.806650 ->exp:-2-> val0[0]val1[98066]
+ * 9.806650000 ->exp:2-> val0[980]val1[665000000]
+ * 9.000806000 ->exp:2-> val0[900]val1[80600000]
+ * 0.174535293 ->exp:2-> val0[17]val1[453529300]
+ * 1.001745329 ->exp:0-> val0[1]val1[1745329]
+ * 1.001745329 ->exp:2-> val0[100]val1[174532900]
+ * 1.001745329 ->exp:4-> val0[10017]val1[453290000]
+ * 9.806650000 ->exp:-2-> val0[0]val1[98066500]
*/
-static void adjust_exponent_micro(int *val0, int *val1, int scale0,
+static void adjust_exponent_nano(int *val0, int *val1, int scale0,
int scale1, int exp)
{
int i;
@@ -285,32 +285,32 @@ static void adjust_exponent_micro(int *v
if (exp > 0) {
*val0 = scale0 * pow_10(exp);
res = 0;
- if (exp > 6) {
+ if (exp > 9) {
*val1 = 0;
return;
}
for (i = 0; i < exp; ++i) {
- x = scale1 / pow_10(5 - i);
+ x = scale1 / pow_10(8 - i);
res += (pow_10(exp - 1 - i) * x);
- scale1 = scale1 % pow_10(5 - i);
+ scale1 = scale1 % pow_10(8 - i);
}
*val0 += res;
*val1 = scale1 * pow_10(exp);
} else if (exp < 0) {
exp = abs(exp);
- if (exp > 6) {
+ if (exp > 9) {
*val0 = *val1 = 0;
return;
}
*val0 = scale0 / pow_10(exp);
rem = scale0 % pow_10(exp);
res = 0;
- for (i = 0; i < (6 - exp); ++i) {
- x = scale1 / pow_10(5 - i);
- res += (pow_10(5 - exp - i) * x);
- scale1 = scale1 % pow_10(5 - i);
+ for (i = 0; i < (9 - exp); ++i) {
+ x = scale1 / pow_10(8 - i);
+ res += (pow_10(8 - exp - i) * x);
+ scale1 = scale1 % pow_10(8 - i);
}
- *val1 = rem * pow_10(6 - exp) + res;
+ *val1 = rem * pow_10(9 - exp) + res;
} else {
*val0 = scale0;
*val1 = scale1;
@@ -332,14 +332,14 @@ int hid_sensor_format_scale(u32 usage_id
unit_conversion[i].unit == attr_info->units) {
exp = hid_sensor_convert_exponent(
attr_info->unit_expo);
- adjust_exponent_micro(val0, val1,
+ adjust_exponent_nano(val0, val1,
unit_conversion[i].scale_val0,
unit_conversion[i].scale_val1, exp);
break;
}
}
- return IIO_VAL_INT_PLUS_MICRO;
+ return IIO_VAL_INT_PLUS_NANO;
}
EXPORT_SYMBOL(hid_sensor_format_scale);
Patches currently in stable-queue which might be from hongyan.song@xxxxxxxxx are
queue-4.4/iio-hid-sensors-increase-the-precision-of-scale-to-fix-wrong-reading-interpretation.patch
queue-4.4/iio-orientation-hid-sensor-rotation-add-pm-function-fix-non-working-driver.patch
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