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FAILED: patch "[PATCH] iio: humidity: hdc100x: Add margin to the conversion time" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Aug 15, 2021

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The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 84edec86f449adea9ee0b4912a79ab8d9d65abb7 Mon Sep 17 00:00:00 2001
From: Chris Lesiak <[email protected]>
Date: Mon, 14 Jun 2021 09:18:20 -0500
Subject: [PATCH] iio: humidity: hdc100x: Add margin to the conversion time

The datasheets have the following note for the conversion time
specification: "This parameter is specified by design and/or characterization and it is not tested in production."

Parts have been seen that require more time to do 14-bit conversions for the relative humidity channel. The result is ENXIO due to the address phase of a transfer not getting an ACK.

Delay an additional 1 ms per conversion to allow for additional margin.

Fixes 4839367d99e3 ("iio: humidity: add HDC100x support")
Signed-off-by Chris Lesiak <[email protected]>
Acked-by Matt Ranostay <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Cc <[email protected]>
Signed-off-by Jonathan Cameron <[email protected]>
drivers/iio/humidity/hdc100x.c +4 -2
index 2a957f19048e..9e0fce917ce4 100644
@@ -25,6 +25,8 @@
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 
+#include <linux/time.h>
+
 #define HDC100X_REG_TEMP			0x00
 #define HDC100X_REG_HUMIDITY			0x01
 

@@ -166,7 +168,7 @@ static int hdc100x_get_measurement(struct hdc100x_data *data,
 				   struct iio_chan_spec const *chan)
 {
 	struct i2c_client *client = data->client;
-	int delay = data->adc_int_us[chan->address];
+	int delay = data->adc_int_us[chan->address] + 1*USEC_PER_MSEC;
 	int ret;
 	__be16 val;
 

@@ -316,7 +318,7 @@ static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct hdc100x_data *data = iio_priv(indio_dev);
 	struct i2c_client *client = data->client;
-	int delay = data->adc_int_us[0] + data->adc_int_us[1];
+	int delay = data->adc_int_us[0] + data->adc_int_us[1] + 2*USEC_PER_MSEC;
 	int ret;
 
 	/* dual read starts at temp register */