This is a note to let you know that I've just added the patch titled
iio: adc: ad7266: 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-ad7266-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 f5e4a9493aadb36dcb798bbb6f6ca226f0e581f1
Author: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Date: Sun May 8 18:55:49 2022 +0100
iio: adc: ad7266: Fix alignment for DMA safety
[ Upstream commit b990cdfe7536a8da7e134d516350402981300016 ]
____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 DMA safety 'may' require separate
cachelines.
Fixes: 54e018da3141 ("iio:ad7266: Mark transfer buffer as __be16")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Acked-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220508175712.647246-10-jic23@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iio/adc/ad7266.c b/drivers/iio/adc/ad7266.c
index c17d9b5fbaf6..53c83e04dde5 100644
--- a/drivers/iio/adc/ad7266.c
+++ b/drivers/iio/adc/ad7266.c
@@ -37,7 +37,7 @@ struct ad7266_state {
struct gpio_desc *gpios[3];
/*
- * DMA (thus cache coherency maintenance) requires the
+ * DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
* The buffer needs to be large enough to hold two samples (4 bytes) and
* the naturally aligned timestamp (8 bytes).
@@ -45,7 +45,7 @@ struct ad7266_state {
struct {
__be16 sample[2];
s64 timestamp;
- } data ____cacheline_aligned;
+ } data __aligned(IIO_DMA_MINALIGN);
};
static int ad7266_wakeup(struct ad7266_state *st)
