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-rw-r--r--drivers/input/touchscreen/ad7877.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/input/touchscreen/ad7877.c b/drivers/input/touchscreen/ad7877.c
index e019d53d1ab..0d2d7e54b46 100644
--- a/drivers/input/touchscreen/ad7877.c
+++ b/drivers/input/touchscreen/ad7877.c
@@ -156,9 +156,14 @@ struct ser_req {
u16 reset;
u16 ref_on;
u16 command;
- u16 sample;
struct spi_message msg;
struct spi_transfer xfer[6];
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ u16 sample ____cacheline_aligned;
};
struct ad7877 {
@@ -182,8 +187,6 @@ struct ad7877 {
u8 averaging;
u8 pen_down_acc_interval;
- u16 conversion_data[AD7877_NR_SENSE];
-
struct spi_transfer xfer[AD7877_NR_SENSE + 2];
struct spi_message msg;
@@ -195,6 +198,12 @@ struct ad7877 {
spinlock_t lock;
struct timer_list timer; /* P: lock */
unsigned pending:1; /* P: lock */
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
};
static int gpio3;