Hi!
Fix this by increasing the delay from 1000-2000 µs to 3000-3300 µs.
Note that this issue has always been present, but it was exposed by the aformentioned commit.
+++ b/drivers/iio/adc/max9611.c @@ -92,6 +92,12 @@ #define MAX9611_TEMP_SCALE_NUM 1000000 #define MAX9611_TEMP_SCALE_DIV 2083 +/*
- Conversion time is 2 ms (typically) at Ta=25 degreeC
- No maximum value is known, so play it safe.
- */
+#define MAX9611_CONV_TIME_US_RANGE 3000, 3300
struct max9611_dev { struct device *dev; struct i2c_client *i2c_client;
This is evil. It looks like a constant, but it is two constants. Just... don't do this.
What about
static inline usleep_conversion(void) { usleep_range(3000, 3300); }
? (Plus, normally we use bigger ranges to make the job of highres infrastructure easier. 3 to 6ms would be typical.)..
Best regards, Pavel
- /*
* need a delay here to make register configuration* stabilize. 1 msec at least, from empirical testing.*/- usleep_range(1000, 2000);
- /* need a delay here to make register configuration stabilize. */
- usleep_range(MAX9611_CONV_TIME_US_RANGE);
ret = i2c_smbus_read_word_swapped(max9611->i2c_client, reg_addr); if (ret < 0) { @@ -510,7 +514,7 @@ static int max9611_init(struct max9611_dev *max9611) MAX9611_REG_CTRL2, 0); return ret; }
- usleep_range(1000, 2000);
- usleep_range(MAX9611_CONV_TIME_US_RANGE);
return 0; }