From: Michael Welling <mwelling@ieee.org>
Date: Wed, 6 May 2015 16:49:17 +0000 (-0500)
Subject: iio: mcp320x: Fix occasional incorrect readings
X-Git-Tag: firefly_0821_release~176^2~1762^2^2~6
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0e81bc99a0826db4cd2d6ba9a982579b1467a79f;p=firefly-linux-kernel-4.4.55.git

iio: mcp320x: Fix occasional incorrect readings

Without the cacheline alignment, the readings will occasionally incorrectly
return 0.

Signed-off-by: Michael Welling <mwelling@ieee.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
---

diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c
index efbfd12a4bfd..8d9c9b9215dd 100644
--- a/drivers/iio/adc/mcp320x.c
+++ b/drivers/iio/adc/mcp320x.c
@@ -60,12 +60,12 @@ struct mcp320x {
 	struct spi_message msg;
 	struct spi_transfer transfer[2];
 
-	u8 tx_buf;
-	u8 rx_buf[2];
-
 	struct regulator *reg;
 	struct mutex lock;
 	const struct mcp320x_chip_info *chip_info;
+
+	u8 tx_buf ____cacheline_aligned;
+	u8 rx_buf[2];
 };
 
 static int mcp320x_channel_to_tx_data(int device_index,