From: Jared Bents <jared.bents@rockwellcollins.com>
Date: Sat, 19 Nov 2016 04:20:38 +0000 (-0600)
Subject: hwmon: (amc6821) sign extension temperature
X-Git-Tag: firefly_0821_release~176^2~4^2~5^2~36
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=firefly-linux-kernel-4.4.55.git;a=commitdiff_plain;h=fbab1832e7e824fe8b588de68914641ac1d61b40

hwmon: (amc6821) sign extension temperature

commit 4538bfbf2d9f1fc48c07ac0cc0ee58716fe7fe96 upstream.

Converts the unsigned temperature values from the i2c read
to be sign extended as defined in the datasheet so that
negative temperatures are properly read.

Fixes: 28e6274d8fa67 ("hwmon: (amc6821) Avoid forward declaration")
Signed-off-by: Jared Bents <jared.bents@rockwellcollins.com>
Signed-off-by: Matt Weber <matthew.weber@rockwellcollins.com>
[groeck: Dropped unnecessary continuation line]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/hwmon/amc6821.c b/drivers/hwmon/amc6821.c
index 12e851a5af48..46b4e35fd555 100644
--- a/drivers/hwmon/amc6821.c
+++ b/drivers/hwmon/amc6821.c
@@ -188,8 +188,8 @@ static struct amc6821_data *amc6821_update_device(struct device *dev)
 			!data->valid) {
 
 		for (i = 0; i < TEMP_IDX_LEN; i++)
-			data->temp[i] = i2c_smbus_read_byte_data(client,
-				temp_reg[i]);
+			data->temp[i] = (int8_t)i2c_smbus_read_byte_data(
+				client, temp_reg[i]);
 
 		data->stat1 = i2c_smbus_read_byte_data(client,
 			AMC6821_REG_STAT1);