Commit f6897dee authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Greg Kroah-Hartman
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iio: hid-sensor-attributes: Fix divisions for 32-bit platforms 



The commit 473d12f7

  ("iio: hid-sensor-attributes: Convert to use int_pow()")

converted to use generic int_pow() helper. Though, the generic one returns
64-bit value and, in cases when it is used as divisor, it compels 64-bit
division from compiler.

In order to fix this, introduce a temporary 32-bit variable to hold the result
of int_pow() and use it as divisor afterwards.

In couple of cases, replace int_pow() with a predefined unit factors for time
and frequency.

Fixes: 473d12f7 ("iio: hid-sensor-attributes: Convert to use int_pow()")
Reported-by: default avatarkbuild test robot <lkp@intel.com>
Reported-by: default avatarNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20190905112759.13035-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 618f40ea

drivers/iio/common/hid-sensors/hid-sensor-attributes.c

+28 −14
Original line number Diff line number Diff line
@@ -10,10 +10,14 @@ 
#include <linux/irq.h>

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/time.h>



#include <linux/hid-sensor-hub.h>

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>



#define HZ_PER_MHZ	1000000L



static struct {

	u32 usage_id;

	int unit; /* 0 for default others from HID sensor spec */
@@ -93,8 +97,10 @@ static void simple_div(int dividend, int divisor, int *whole, 


static void split_micro_fraction(unsigned int no, int exp, int *val1, int *val2)

{

	*val1 = no / int_pow(10, exp);

	*val2 = no % int_pow(10, exp) * int_pow(10, 6 - exp);

	int divisor = int_pow(10, exp);



	*val1 = no / divisor;

	*val2 = no % divisor * int_pow(10, 6 - exp);

}



/*
@@ -129,6 +135,7 @@ static void convert_from_vtf_format(u32 value, int size, int exp, 


static u32 convert_to_vtf_format(int size, int exp, int val1, int val2)

{

	int divisor;

	u32 value;

	int sign = 1;
@@ -136,10 +143,13 @@ static u32 convert_to_vtf_format(int size, int exp, int val1, int val2) 
		sign = -1;

	exp = hid_sensor_convert_exponent(exp);

	if (exp < 0) {

		divisor = int_pow(10, 6 + exp);

		value = abs(val1) * int_pow(10, -exp);

		value += abs(val2) / int_pow(10, 6 + exp);

	} else

		value = abs(val1) / int_pow(10, exp);

		value += abs(val2) / divisor;

	} else {

		divisor = int_pow(10, exp);

		value = abs(val1) / divisor;

	}

	if (sign < 0)

		value =  ((1LL << (size * 8)) - value);
@@ -202,12 +212,12 @@ int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st, 
	if (val1 < 0 || val2 < 0)

		return -EINVAL;



	value = val1 * int_pow(10, 6) + val2;

	value = val1 * HZ_PER_MHZ + val2;

	if (value) {

		if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND)

			value = int_pow(10, 9) / value;

			value = NSEC_PER_SEC / value;

		else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND)

			value = int_pow(10, 6) / value;

			value = USEC_PER_SEC / value;

		else

			value = 0;

	}
@@ -296,6 +306,7 @@ EXPORT_SYMBOL(hid_sensor_write_raw_hyst_value); 
static void adjust_exponent_nano(int *val0, int *val1, int scale0,

				  int scale1, int exp)

{

	int divisor;

	int i;

	int x;

	int res;
@@ -309,9 +320,10 @@ static void adjust_exponent_nano(int *val0, int *val1, int scale0, 
			return;

		}

		for (i = 0; i < exp; ++i) {

			x = scale1 / int_pow(10, 8 - i);

			divisor = int_pow(10, 8 - i);

			x = scale1 / divisor;

			res += int_pow(10, exp - 1 - i) * x;

			scale1 = scale1 % int_pow(10, 8 - i);

			scale1 = scale1 % divisor;

		}

		*val0 += res;

		*val1 = scale1 * int_pow(10, exp);
@@ -321,13 +333,15 @@ static void adjust_exponent_nano(int *val0, int *val1, int scale0, 
			*val0 = *val1 = 0;

			return;

		}

		*val0 = scale0 / int_pow(10, exp);

		rem = scale0 % int_pow(10, exp);

		divisor = int_pow(10, exp);

		*val0 = scale0 / divisor;

		rem = scale0 % divisor;

		res = 0;

		for (i = 0; i < (9 - exp); ++i) {

			x = scale1 / int_pow(10, 8 - i);

			divisor = int_pow(10, 8 - i);

			x = scale1 / divisor;

			res += int_pow(10, 8 - exp - i) * x;

			scale1 = scale1 % int_pow(10, 8 - i);

			scale1 = scale1 % divisor;

		}

		*val1 = rem * int_pow(10, 9 - exp) + res;

	} else {

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