This is a note to let you know that I've just added the patch titled
iio: adc: ad7768-1: Fix alignment for DMA safety
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iio-adc-ad7768-1-fix-alignment-for-dma-safety.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a2cd3ba767729fbb767f879fad4999799a20aeb4
Author: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Date: Sun May 8 18:55:56 2022 +0100
iio: adc: ad7768-1: Fix alignment for DMA safety
[ Upstream commit 211f810f8fae05c1f78e531b2b113ea1ab3d1ce7 ]
____cacheline_aligned is an insufficient guarantee for non-coherent DMA
on platforms with 128 byte cachelines above L1. Switch to the updated
IIO_DMA_MINALIGN definition.
Update the comment to reflect that separate cachelines 'may' be
required.
Fixes: a5f8c7da3dbe ("iio: adc: Add AD7768-1 ADC basic support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Acked-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220508175712.647246-17-jic23@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
index aa42ba759fa1..60f394da4640 100644
--- a/drivers/iio/adc/ad7768-1.c
+++ b/drivers/iio/adc/ad7768-1.c
@@ -163,7 +163,7 @@ struct ad7768_state {
struct gpio_desc *gpio_sync_in;
const char *labels[ARRAY_SIZE(ad7768_channels)];
/*
- * DMA (thus cache coherency maintenance) requires the
+ * DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
*/
union {
@@ -173,7 +173,7 @@ struct ad7768_state {
} scan;
__be32 d32;
u8 d8[2];
- } data ____cacheline_aligned;
+ } data __aligned(IIO_DMA_MINALIGN);
};
static int ad7768_spi_reg_read(struct ad7768_state *st, unsigned int addr,
