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[75/92] iio: gyro: fxas210002c: Fix alignment for DMA safety

Message ID 20220503085935.1533814-76-jic23@kernel.org (mailing list archive)
State Superseded
Headers show
Series IIO: Fix alignment of buffers for DMA | expand

Commit Message

Jonathan Cameron May 3, 2022, 8:59 a.m. UTC
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

____cacheline_aligned is an insufficient guarantee for non-coherent DMA
on platforms with 128 byte cachelines above L1.  Switch to the updated
IIO_ALIGN definition.

Updated the comment to 'may' require.

Fixes: a0701b6263ae ("iio: gyro: add core driver for fxas21002c")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Rui Miguel Silva <rui.silva@linaro.org>
---
 drivers/iio/gyro/fxas21002c_core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Rui Miguel Silva May 3, 2022, 12:14 p.m. UTC | #1
Hi Jonathan,
Thanks for fixing this.

On Tue, May 03, 2022 at 09:59:18AM +0100, Jonathan Cameron wrote:
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> ____cacheline_aligned is an insufficient guarantee for non-coherent DMA
> on platforms with 128 byte cachelines above L1.  Switch to the updated
> IIO_ALIGN definition.
> 
> Updated the comment to 'may' require.
> 
> Fixes: a0701b6263ae ("iio: gyro: add core driver for fxas21002c")
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Rui Miguel Silva <rui.silva@linaro.org>

Reviewed-by: Rui Miguel Silva <rui.silva@linaro.org>

Cheers,
   Rui
> ---
>  drivers/iio/gyro/fxas21002c_core.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/gyro/fxas21002c_core.c b/drivers/iio/gyro/fxas21002c_core.c
> index 410e5e9f2672..d89dab48956a 100644
> --- a/drivers/iio/gyro/fxas21002c_core.c
> +++ b/drivers/iio/gyro/fxas21002c_core.c
> @@ -150,10 +150,10 @@ struct fxas21002c_data {
>  	struct regulator *vddio;
>  
>  	/*
> -	 * DMA (thus cache coherency maintenance) requires the
> -	 * transfer buffers to live in their own cache lines.
> +	 * DMA (thus cache coherency maintenance) may require the
> +	 * transfer buffers live in their own cache lines.
>  	 */
> -	s16 buffer[8] ____cacheline_aligned;
> +	s16 buffer[8] __aligned(IIO_ALIGN);
>  };
>  
>  enum fxas21002c_channel_index {
> -- 
> 2.36.0
>
diff mbox series

Patch

diff --git a/drivers/iio/gyro/fxas21002c_core.c b/drivers/iio/gyro/fxas21002c_core.c
index 410e5e9f2672..d89dab48956a 100644
--- a/drivers/iio/gyro/fxas21002c_core.c
+++ b/drivers/iio/gyro/fxas21002c_core.c
@@ -150,10 +150,10 @@  struct fxas21002c_data {
 	struct regulator *vddio;
 
 	/*
-	 * DMA (thus cache coherency maintenance) requires the
-	 * transfer buffers to live in their own cache lines.
+	 * DMA (thus cache coherency maintenance) may require the
+	 * transfer buffers live in their own cache lines.
 	 */
-	s16 buffer[8] ____cacheline_aligned;
+	s16 buffer[8] __aligned(IIO_ALIGN);
 };
 
 enum fxas21002c_channel_index {