This is a note to let you know that I've just added the patch titled
iio: adc: ad_sigma_delta: ensure proper DMA alignment
to the 6.6-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-ad_sigma_delta-ensure-proper-dma-alignment.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 59598510be1d49e1cff7fd7593293bb8e1b2398b Mon Sep 17 00:00:00 2001
From: Nuno Sa <nuno.sa@xxxxxxxxxx>
Date: Wed, 17 Jan 2024 13:41:03 +0100
Subject: iio: adc: ad_sigma_delta: ensure proper DMA alignment
From: Nuno Sa <nuno.sa@xxxxxxxxxx>
commit 59598510be1d49e1cff7fd7593293bb8e1b2398b 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 the sigma_delta ADCs.
[1]: https://lore.kernel.org/linux-iio/20220508175712.647246-2-jic23@xxxxxxxxxx/
Fixes: 0fb6ee8d0b5e ("iio: ad_sigma_delta: Don't put SPI transfer buffer on the stack")
Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240117-dev_sigma_delta_no_irq_flags-v1-1-db39261592cf@xxxxxxxxxx
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/iio/adc/ad_sigma_delta.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/include/linux/iio/adc/ad_sigma_delta.h
+++ b/include/linux/iio/adc/ad_sigma_delta.h
@@ -8,6 +8,8 @@
#ifndef __AD_SIGMA_DELTA_H__
#define __AD_SIGMA_DELTA_H__
+#include <linux/iio/iio.h>
+
enum ad_sigma_delta_mode {
AD_SD_MODE_CONTINUOUS = 0,
AD_SD_MODE_SINGLE = 1,
@@ -99,7 +101,7 @@ struct ad_sigma_delta {
* 'rx_buf' is up to 32 bits per sample + 64 bit timestamp,
* rounded to 16 bytes to take into account padding.
*/
- uint8_t tx_buf[4] ____cacheline_aligned;
+ uint8_t tx_buf[4] __aligned(IIO_DMA_MINALIGN);
uint8_t rx_buf[16] __aligned(8);
};
Patches currently in stable-queue which might be from nuno.sa@xxxxxxxxxx are
queue-6.6/iio-imu-adis-ensure-proper-dma-alignment.patch
queue-6.6/iio-adc-ad_sigma_delta-ensure-proper-dma-alignment.patch
queue-6.6/iio-adc-ad4130-zero-initialize-clock-init-data.patch
queue-6.6/iio-commom-st_sensors-ensure-proper-dma-alignment.patch
queue-6.6/iio-adc-ad4130-only-set-gpio_ctrl-if-pin-is-unused.patch
