From 2952cd9b7c7f776e5eea5a06ab73aa356a8ca939 Mon Sep 17 00:00:00 2001 From: Nuno Sa Date: Wed, 31 Jan 2024 10:16:47 +0100 Subject: [PATCH] iio: commom: st_sensors: ensure proper DMA alignment commit 862cf85fef85becc55a173387527adb4f076fab0 upstream. Aligning the buffer to the L1 cache is not sufficient in some platforms as they might have larger cacheline sizes for caches after L1 and thus, we can't guarantee DMA safety. That was the whole reason to introduce IIO_DMA_MINALIGN in [1]. Do the same for st_sensors common buffer. While at it, moved the odr_lock before buffer_data as we definitely don't want any other data to share a cacheline with the buffer. [1]: https://lore.kernel.org/linux-iio/20220508175712.647246-2-jic23@kernel.org/ Fixes: e031d5f558f1 ("iio:st_sensors: remove buffer allocation at each buffer enable") Signed-off-by: Nuno Sa Cc: Link: https://lore.kernel.org/r/20240131-dev_dma_safety_stm-v2-1-580c07fae51b@analog.com Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- include/linux/iio/common/st_sensors.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h index 607c3a89a6471..f9ae5cdd884f5 100644 --- a/include/linux/iio/common/st_sensors.h +++ b/include/linux/iio/common/st_sensors.h @@ -258,9 +258,9 @@ struct st_sensor_data { bool hw_irq_trigger; s64 hw_timestamp; - char buffer_data[ST_SENSORS_MAX_BUFFER_SIZE] ____cacheline_aligned; - struct mutex odr_lock; + + char buffer_data[ST_SENSORS_MAX_BUFFER_SIZE] __aligned(IIO_DMA_MINALIGN); }; #ifdef CONFIG_IIO_BUFFER -- 2.47.3